[LLDB] Fix UBSan issue with ValueType enums. (#195540)
ValueTypeSyntheticMask, when bitwise OR'd with ValueType enums, produces
a value that is outside the official enum range for ValueTypes. This
causes UBSan errors, when UBSan is set to check enum values. E.g. If you
build LLDB with the Cmake flags
-DCMAKE_CXX_FLAGS="-fsanitize=enum -fsanitize-trap=enum"
-DCMAKE_C_FLAGS="-fsanitize=enum -fsanitize-trap=enum"
Then try to run the LLDB test TestScripedFrameProvider, it crashes with
a SIGILL from UBSan.
This change fixes that by pulling ValueTypeSyntheticMask into the
ValueType enums, expanding the valid enum range and making the bitwise
OR'd values valid.
