[clang] [llvm] Add option to generate additional debug info for expression dereferencing pointer to pointers. (PR #81545)

[William Junda Huang via cfe-commits]

huangjd wrote:

> Reading LLVM IR lit CHECK lines from clang codegen is a bit difficult - could you include some simple examples (perhaps from the new clang tests in this patch) showing the DWARF output just as comments in this review for something more easily glanceable?

Attached is the output of the following command 

`clang ~/llvm-project/clang/test/CodeGenCXX/debug-info-ptr-to-ptr.cpp  -fdebug-info-for-pointer-type -g2 -S -O3  -o /tmp/debug-info-ptr-to-ptr.txt`

[debug-info-ptr-to-ptr.txt](https://github.com/llvm/llvm-project/files/14659111/debug-info-ptr-to-ptr.txt)


https://github.com/llvm/llvm-project/pull/81545