Add a trampoline attribute to clang, which indicates to debuggers that stepping into the function should jump to the argument passed in the attribute instead.

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.

Add a trampoline attribute to clang, which indicates to debuggers thatmeant 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.