Merge branch 'fixup_sm_60_wording' of https://github.com/sheredom/glslang into sheredom-fixup_sm_60_wording

Now, version 5.* is all connected to making the uint type, which doesn't quite work.
Generator versions 4 and 6 do not do this.

SPV: Implement Vulkan 1.1 features and extensions.

This reverts commit 2c65069e, reversing
changes made to fa9b465b.

Legalization: Omit legalization warning when spirv-opt is linked.

Update spirv-tools known_good

Add more error checks for interpolateAtVertexAMD()

Still missing is automation and final decisions on mechanisms in general.

Implement the extension GL_AMD_gpu_shader_half_float_fetch

Fix issues of SPIRV headers

- Support new opaque types: f16sampler*, f16image*, f16subpassInput*.
- Add new built-in GLSL texture/image functions.

Fix typo in help for -V<bad-number>

EShLangFragment falls through to EShLangCompute, only #ifndef AMD_EXTENSIONS.

EShLangFragment falls through to EShLangCompute, only #ifndef AMD_EXTENSIONS.
This is probably a bug.

This factored computeTypeLocationSize() out of needing the TIntermediate contents,
and uses it to show how to know how many locations an object needs.
However, it still does not do cross stage, or mixed location/no-location
analysis.

Contains the following improvements:

Fixes 1341: Atomics (and other instructions with side-effects) removed.
Add folding for redundant add/sub/mul/div/mix operations
Add constant folding rules for floating-point comparison
Add folding of redundant OpSelect insns
Add folding of OpCompositeExtract and OpConstantComposite

Constants were generally cached by type opcode, but all structures share the
same type opcode (OpTypeStruct), so they need to be cached by type id.