Add a trampoline attribute to clang, meant to be used by in compiler generated code, which indicates to debuggers that stepping into the function should jump to the argument passed in the attribute instead.

The `transparent_stepping` attribute is intended as a hint for debuggers that this function itself is not interesting, but it calls a function that might be. So, when stepping in arrives at a function with this attribute, debuggers should transparently step-in through it into the functions called by the annotated function (but not by subsequent calls made by those functions), stopping at the first one its normal rules for whether to stop says to stop at - or stepping out again if none qualify. Also, when stepping out arrives at a function with this attribute, the debugger should continue stepping out to its caller.

Add a trampolineThe `transparent_stepping` attribute to clang, meant to be used by in compileris intended as a hint for generated codedebuggers that this function itself is not interesting, which indicates to debuggers thatbut it calls a stepping into the function should jump to the argument passed in thefunction that might be. So, when stepping in arrives at a function attribute insteadwith this attribute, debuggers should transparently step-in through it into the functions called by the annotated function (but not by subsequent calls made by those functions), stopping at the first one its normal rules for whether to stop says to stop at - or stepping out again if none qualify. Also, when stepping out arrives at a function with this attribute, the debugger should continue stepping out to its caller.