In https://reviews.llvm.org/D80833, there were concerns about
determinism emitting the commandline into CodeView. We're actually
hitting these when running clang-cl on Linux (cross compiling) versus on
Windows (e.g. -fmessage-length being inferred on terminals).
Add -g[no-]codeview-command-line to enable/disable this feature.
It's still on by default to preserve the current state of clang.
Reviewed By: thakis, rnk
Differential Revision: https://reviews.llvm.org/D136474
Arthur Eubanks