In https://gcc.gnu.org/PR103598 we found out that gcc-12
changed __PRETTY_FUNCTION__ slightly and broke llvm-12 (and older)
tests that rely on exact type match. llvm-13 already removed the
qualified names from the expected output.
This change changes expected output to avoid llvm:: namespace prefix.
This is enough to get tests pass on x86_64 again.
Tested against this week's gcc-12 and against gcc-10.