[llvm] [DiagnosticInfo] Output full file path instead of relative path (PR #68027)

[Arthur Eubanks via llvm-commits]

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@@ -159,7 +159,10 @@ std::string DiagnosticInfoWithLocationBase::getLocationStr() const {
   unsigned Column = 0;
   if (isLocationAvailable())
     getLocation(Filename, Line, Column);
-  return (Filename + ":" + Twine(Line) + ":" + Twine(Column)).str();
+  return (getAbsolutePath()
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aeubanks wrote:

can we just always use `getAbsolutePath()`? or else we'll get inconsistent behavior

https://github.com/llvm/llvm-project/pull/68027