`grep` within source code

e.g. when GPUCompiler says `unsupported dynamic function invocation (call to convert)` and you want to check the IR to find all calls to `convert`.

Something like: `@code_for :cuda_llvm filter="convert" f()` or `@code_for :cuda_typed filter=Base.convert f()`

With some options to have X context lines above or below each match.