clang emit Duplicate file entry on windows

Hi Devs,
clang Emitting duplicate file entry when the input file given like this
$./clang++ -g -c -o test.o

$./llvm-dwarfdump -debug-line test.o

Is this
which had a tentative patch at ⚙ D71508 [DebugInfo] Duplicate file names in debug info ?
The original complaint wasn't for Windows, but the lack of
filepath canonicalization seems like a common symptom.