[clang] [clang][DebugInfo] Add call site debug info flag (PR #169574)

[J. Ryan Stinnett via cfe-commits]

jryans wrote:

Here's a diff of recent Clang compiled using `-O2 -g` on Linux with and without the new `-gno-call-site-info` flag:

```
    FILE SIZE        VM SIZE    
 --------------  -------------- 
  +0.0%     +12  [ = ]       0    .eh_frame
  -0.0% -1.50Ki  -0.0% -1.50Ki    .rodata
 -30.3% -2.51Ki  [ = ]       0    [Unmapped]
  -2.0% -7.57Ki  [ = ]       0    .debug_line_str
  -0.3% -75.7Ki  [ = ]       0    .debug_rnglists
  -0.0%  -146Ki  [ = ]       0    .debug_str
  -0.1%  -209Ki  [ = ]       0    .debug_loclists
  -2.6%  -307Ki  [ = ]       0    .debug_abbrev
  -0.7%  -744Ki  [ = ]       0    .debug_line
  -1.0% -1.08Mi  [ = ]       0    .debug_str_offsets
 -20.1% -9.01Mi  [ = ]       0    .debug_addr
  -4.4% -32.8Mi  [ = ]       0    .debug_info
  -2.6% -44.4Mi  -0.0% -1.50Ki    TOTAL
```

As expected, disabling call site info reduces binary size (2.6% overall), confirming size is reduced even further than the amount added by the recent change in https://github.com/llvm/llvm-project/pull/166202.

https://github.com/llvm/llvm-project/pull/169574