[llvm] [VFABI] Improve VFABI unit tests (PR #73907)

[Maciej Gabka via llvm-commits]

================
@@ -61,40 +61,31 @@ class VFABIParserTest : public ::testing::Test {
   // use to create the function in the module if it differs from the
   // standard mangled name.
   //
-  // \p IRType -> FunctionType string to be used for the signature of
+  // \p STy -> FunctionType string to be used for the signature of
----------------
mgabka wrote:

should be SFunty, and the the description does not match as this is the FunctionType of the scalar function as described in tryDemangleForVFABI

https://github.com/llvm/llvm-project/pull/73907