The changes to glslang/glslang/MachineIndependent/ParseHelper.cpp exist
purely to prevent even more instances of "warning: enumeration value
‘EOp...’ not handled in switch"
v2: Remove 8-bit types. Overzealous copy-and-paste led to adding
support for a bunch of types that the extension doesn't actually enable.
v3: Update expected test results file. Just changing an expected
results file to make a test pass seems sketchy to me, but I'm not sure
what else to do.
v4: Add missing entry for EOpAbsDifference in
TOutputTraverser::visitBinary. Noticed by JohnK.
