Clean up qualification order checks Move determining whether qualification order checks are relaxed to QualifierTypes.cpp. The ParseContext only needs to construct TTypeQualifierBuilder with the shader version as a parameter, and it will make the decision based on that. ParseContext still passes diagnostics to the TTypeQualifierBuilder functions that return variable qualification to make it more explicit when errors are generated. Also encapsulate looking for symbols in the AST inside compiler_test.cpp. BUG=angleproject:1442 TEST=angle_unittests Change-Id: I4190e6a680ace0cc0568a517e86353a95cc63c08 Reviewed-on: https://chromium-review.googlesource.com/380556 Commit-Queue: Olli Etuaho <oetuaho@nvidia.com> Reviewed-by: Corentin Wallez <cwallez@chromium.org>