-Wcomma-in-init should maybe be more aggressive?

Description

Had a bug on a compute shader. Spent quite some time to figure out what's the issue (concurrent read/write to some buffers from multiple threads, etc, so LOTS of places things could go wrong).
Turns out the issue is simple:

uint thread_count = 32;
uint width = 4096
uint height = 2048
uint2 size = (width, height) / thread_count

I had forgotten the uint2 in the initializer:

uint2 size = uint2(width, height) / thread_count

Steps to Reproduce

[numthreads(1, 1, 1)]
void main()
{
  uint2 a = (1, 2) / 2;
}

dxc -T cs_6_6 repro.hlsl -Od

Dxc builds with no complaints.

Actual Behavior

Maybe DXC should complain that a constructor list may have been intended?
This code does generates the warning:

[numthreads(1, 1, 1)]
void main()
{
  uint2 a = (1, 2);
}

Environment

• DXC version: libdxcompiler.so: 1.7(dev;4028-56db6cef)
• DXC hash: 1d6b5627ac46a8b433f21fae50b9192689336c15
• Host Operating system: linux

Start by running the reported dxc command on repro.hlsl and compare the existing -Wcomma-in-init behavior for the two examples. Trace the compiler warning implementation and its diagnostic tests to determine where parenthesized comma expressions in arithmetic should be checked. Done means the intended case produces a warning without introducing false positives, with regression coverage.