HLSL: allow self-type cast (as no-op passthrough)

Previously, casting an object of a struct type to an identical type
would produce an error.  This PR allows this case.

As a side-effect of the change, several self-type casts in existing
tests go away.  For example:

    0:10          Construct float ( temp float)
    0:10            'f' ( in float)

becomes this (without the unneeded constructor op):

    0:10          'f' ( in float)

For vector or array types this can result in somewhat less overall code.

Fixes: #1218

HLSL: require coverage mask to be arrayed output.

Fix issue #1376: SPV_AMD_gpu_shader_half_float is not emitted under vulkan1.1

vulkan1.1

Interpolation functions, using 16-bit interpolants, should always emit
this extension string regardless of vulkan enviornment version.

SPIR-V requires the coverage mask to be an array of integers, but HLSL
allows scalar integers.  This adds the requisite type conversion and
wrapped entry point handling.

Fixes: #1202

HLSL: various SPIR-V compute shader IDs must be 3-vectors of integers

This PR forces the external definition of SV_GroupID variables to 3-vectors.
The conversion process between the shader-declared type and the external type
happens in wrapped main IO variable conversion.

The same applies to SV_DispatchThreadID and SV_GroupThreadID.

Fixes: #1371

HLSL: Allow stream output Append() method after entry point.

Append() method is special: unlike most outputs, it does not copy
some temporary data to a symbol in the entry point epilogue, but
rather uses an emit builtin after each write to the output stream.

This had been handled by remembering the special output symbol for
the stream as it was declared in the shader entry point before
symbol sanitization.  However the prior code was too simple and
only handled cases where the Append() method happened after the
entry point, so that the output symbol had been seen.

This PR adds a patching step so that the Append()s may appear in
any order WRT the entry point.  They are patched in an epilogue,
whereupon it is guaranteed in a well formed shader that we have
seen the appropriate declaration.

Fixes #1217.

Skip outermost array when assigning locations to auto-array interfaces

We want these tests to be independent of whether SPIRV-opt is used.

When assigning a location to an interface whose stage automatically
converts the interfaces to an array, it now strips off the outermost
array from the type before calculating how many locations it consumes.

Fix #944: Convert argument type to match formal parameter type.

Update spirv-opt known-good

Notably, this includes the following:

- Fix exponential performance of DeadInsertElim
- Constant folding of OpVectorTimesScalar
- Add Vector DCE
- Add store-store elimination to LocalSingleBlockElim
- Improve folding of OpVectorTimesScalar and OpPhi
- Fixes handling of kill and unreachable ops in inlining

Fixed install for SPIRV, glslang, and hlsl when building shared libs

Fix issue #1367 - change the I/O remapper to ignore push constants so…

Fix issue #1367 - change the I/O remapper to ignore push constants so it does not apply a binding/descriptor set to them.

Update known-good.

Notably, reduces spirv-opt time and adds folding of OpDot and OpFNegate.

Initial way of addressing #1362.

Add AMD float16/int16 SPV extension string when GLSL specifies them

exp operand