[OpenMP] Add function tracing debugging to device RTL

This patch adds support for an RAII struct that will print function
traces when placed inside of a function declaration. Each successive
call will increase the indentation to make it easier to visually
inspect.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D110202

GitOrigin-RevId: 277b681edec2ee4394c7e62a118ad21b2cbbb227
4 files changed