[rbi] Remove highlights from errors.

I have noticed over time when working on the command line, we often times
highlight too large of an expression due to the locations provided to us by
earlier parts of the compiler. This isn't technically necessary and the
following doesn't look nice... so remove it.

```
test5.swift:171:16: error: sending 'x' risks causing data races [#SendingRisksDataRace]
169 |   let _ = {
170 |     nonescapingAsyncUse { @mainactor in
171 | _� _� _� _� _�u_�s_�e_�V_�a_�l_�u_�e_�(_�x_�)
    |                |- error: sending 'x' risks causing data races [#SendingRisksDataRace]
    |                `- note: task-isolated 'x' is captured by a main actor-isolated closure. main actor-isolated uses in closure may race against later nonisolated uses
172 |     }
173 |   }
```

Author: gottesmm

lib/SILOptimizer/Mandatory/SendNonSendable.cpp

@@ -894,7 +894,6 @@ class UseAfterSendDiagnosticEmitter {
                                   ApplyIsolationCrossing isolationCrossing) {
     // Emit the short error.
     diagnoseError(loc, diag::regionbasedisolation_named_send_yields_race, name)
-        .highlight(loc.getSourceRange())
         .limitBehaviorIf(getBehaviorLimit());
 
     // Then emit the note with greater context.
@@ -928,7 +927,6 @@ class UseAfterSendDiagnosticEmitter {
                                   const ValueDecl *callee) {
     // Emit the short error.
     diagnoseError(loc, diag::regionbasedisolation_named_send_yields_race, name)
-        .highlight(loc.getSourceRange())
         .limitBehaviorIf(getBehaviorLimit());
 
     // Then emit the note with greater context.
@@ -953,7 +951,6 @@ class UseAfterSendDiagnosticEmitter {
                                                  Identifier name) {
     // Emit the short error.
     diagnoseError(loc, diag::regionbasedisolation_named_send_yields_race, name)
-        .highlight(loc.getSourceRange())
         .limitBehaviorIf(getBehaviorLimit());
 
     diagnoseNote(
@@ -965,7 +962,6 @@ class UseAfterSendDiagnosticEmitter {
                                   ApplyIsolationCrossing isolationCrossing) {
     diagnoseError(loc, diag::regionbasedisolation_type_send_yields_race,
                   inferredType)
-        .highlight(loc.getSourceRange())
         .limitBehaviorIf(getBehaviorLimit());
 
     auto calleeIsolationStr =
@@ -989,14 +985,12 @@ class UseAfterSendDiagnosticEmitter {
   void emitNamedUseofStronglySentValue(SILLocation loc, Identifier name) {
     // Emit the short error.
     diagnoseError(loc, diag::regionbasedisolation_named_send_yields_race, name)
-        .highlight(loc.getSourceRange())
         .limitBehaviorIf(getBehaviorLimit());
 
     // Then emit the note with greater context.
     diagnoseNote(
         loc, diag::regionbasedisolation_named_value_used_after_explicit_sending,
-        name)
-        .highlight(loc.getSourceRange());
+        name);
 
     // Finally the require points.
     emitRequireInstDiagnostics();
@@ -1005,7 +999,6 @@ class UseAfterSendDiagnosticEmitter {
   void emitTypedUseOfStronglySentValue(SILLocation loc, Type inferredType) {
     diagnoseError(loc, diag::regionbasedisolation_type_send_yields_race,
                   inferredType)
-        .highlight(loc.getSourceRange())
         .limitBehaviorIf(getBehaviorLimit());
     if (auto callee = getSendingCallee()) {
       diagnoseNote(loc,
@@ -1024,7 +1017,6 @@ class UseAfterSendDiagnosticEmitter {
       ApplyIsolationCrossing isolationCrossing) {
     // Emit the short error.
     diagnoseError(loc, diag::regionbasedisolation_named_send_yields_race, name)
-        .highlight(loc.getSourceRange())
         .limitBehaviorIf(getBehaviorLimit());
 
     auto descriptiveKindStr =
@@ -1039,8 +1031,7 @@ class UseAfterSendDiagnosticEmitter {
     diagnoseNote(loc,
                  diag::regionbasedisolation_named_isolated_closure_yields_race,
                  isDisconnected, descriptiveKindStr, name, calleeIsolationStr,
-                 callerIsolationStr)
-        .highlight(loc.getSourceRange());
+                 callerIsolationStr);
     emitRequireInstDiagnostics();
   }
 
@@ -1049,7 +1040,6 @@ class UseAfterSendDiagnosticEmitter {
       ApplyIsolationCrossing isolationCrossing) {
     diagnoseError(loc, diag::regionbasedisolation_type_send_yields_race,
                   inferredType)
-        .highlight(loc.getSourceRange())
         .limitBehaviorIf(getBehaviorLimit());
 
     auto calleeIsolationStr =
@@ -1125,14 +1115,12 @@ class UseAfterSendDiagnosticEmitter {
       auto require = requireInsts.pop_back_val();
       switch (require.getKind()) {
       case RequireInst::UseAfterSend:
-        diagnoseNote(*require, diag::regionbasedisolation_maybe_race)
-            .highlight(require->getLoc().getSourceRange());
+        diagnoseNote(*require, diag::regionbasedisolation_maybe_race);
         continue;
       case RequireInst::InOutReinitializationNeeded:
         diagnoseNote(
             *require,
-            diag::regionbasedisolation_inout_sending_must_be_reinitialized)
-            .highlight(require->getLoc().getSourceRange());
+            diag::regionbasedisolation_inout_sending_must_be_reinitialized);
         continue;
       }
       llvm_unreachable("Covered switch isn't covered?!");
@@ -1598,7 +1586,6 @@ class SendNeverSentDiagnosticEmitter {
                        ApplyIsolationCrossing crossing) {
     diagnoseError(loc, diag::regionbasedisolation_type_send_yields_race,
                   inferredType)
-        .highlight(loc.getSourceRange())
         .limitBehaviorIf(getBehaviorLimit());
 
     auto descriptiveKindStr =
@@ -1635,15 +1622,13 @@ class SendNeverSentDiagnosticEmitter {
     diagnoseNote(loc,
                  diag::regionbasedisolation_named_isolated_closure_yields_race,
                  isDisconnected, descriptiveKindStr, name, calleeIsolationStr,
-                 callerIsolationStr)
-        .highlight(loc.getSourceRange());
+                 callerIsolationStr);
   }
 
   void emitTypedSendingNeverSendableToSendingParam(SILLocation loc,
                                                    Type inferredType) {
     diagnoseError(loc, diag::regionbasedisolation_type_send_yields_race,
                   inferredType)
-        .highlight(loc.getSourceRange())
         .limitBehaviorIf(getBehaviorLimit());
 
     auto descriptiveKindStr =
@@ -1742,7 +1727,6 @@ class SendNeverSentDiagnosticEmitter {
       diagnoseError(loc,
                     diag::regionbasedisolation_typed_tns_passed_sending_closure,
                     descriptiveKindStr)
-          .highlight(loc.getSourceRange())
           .limitBehaviorIf(behaviorLimit);
     };
 
@@ -1798,7 +1782,6 @@ class SendNeverSentDiagnosticEmitter {
 
   void emitNamedOnlyError(SILLocation loc, Identifier name) {
     diagnoseError(loc, diag::regionbasedisolation_named_send_yields_race, name)
-        .highlight(getOperand()->getUser()->getLoc().getSourceRange())
         .limitBehaviorIf(getBehaviorLimit());
   }