[CMake] Fix usage of lowercase or in condition (#1117)

CMake is a strange animal and some things are case sensitive, while
others aren't. It seems that `if(<condition>)` logical operator `OR` is
case sensitive, and `or` was not cutting it. At least for CMake 3.26.4.

If some CMake version allows `or`, it should also allow `OR`, so this
change should not be a problem for those versions.

Most of the time these pieces are not actually hit, because the build
system sets `SwiftTesting_MACROS` to `NO`, so this is skipped, which
might explain why it has not been a problem.

Author: drodriguez

Sources/CMakeLists.txt

@@ -66,7 +66,7 @@ if(SwiftTesting_MACRO STREQUAL "<auto>")
   if(NOT SwiftTesting_BuildMacrosAsExecutables)
     if(CMAKE_HOST_SYSTEM_NAME STREQUAL "Darwin")
       set(SwiftTesting_MACRO_PATH "${SwiftTesting_MACRO_INSTALL_PREFIX}/lib/swift/host/plugins/testing/libTestingMacros.dylib")
-    elseif(CMAKE_HOST_SYSTEM_NAME STREQUAL "Linux" or CMAKE_HOST_SYSTEM_NAME STREQUAL "FreeBSD")
+    elseif(CMAKE_HOST_SYSTEM_NAME STREQUAL "Linux" OR CMAKE_HOST_SYSTEM_NAME STREQUAL "FreeBSD")
       set(SwiftTesting_MACRO_PATH "${SwiftTesting_MACRO_INSTALL_PREFIX}/lib/swift/host/plugins/libTestingMacros.so")
     elseif(CMAKE_HOST_SYSTEM_NAME STREQUAL "Windows")
       set(SwiftTesting_MACRO_PATH "${SwiftTesting_MACRO_INSTALL_PREFIX}/bin/TestingMacros.dll")