This reverts commit ad08b30f696267ec6243dd0ad68a3db889cd2d21, reversing
changes made to 28660bb580d4c61e16ef75008550a87b3be90b91.
This backs out the pull request
https://github.com/KhronosGroup/glslang/pull/456 because it introduced
several internal errors even on code that only uses 32-bit numeric
types.