SPIR-V OpLines now contain filenames from HLSL-style #lines.

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

It was missing when there were no semantics.

Enabled via -fhlsl_functionality1

This is to create more stable test results.

Adds command line options:

   --invert-y
   --iy

(synonyms) which invert position.Y on vertex shader output.  Handles these cases:

* Direct single variable return
* Member of direct returned struct
* Single variable output parameter
* Member of struct output parameter

API:

    // Enables position.Y output negation in vertex shader
    void TShader::setInvertY(bool invert);

Fixes #1173

Per feedback on PR #1111, this reverses the order of the parameters for the setShiftBinding API.

It is now:

    void TShader::setShiftBindingForSet(TResourceType res, unsigned int base, unsigned int set);

This PR adds the ability to provide per-descriptor-set IO mapping shift
values.  If a particular binding does not land into a per-set value,
then it falls back to the prior behavior (global shifts per resource class).

Because there were already 6 copies of many different methods and internal
variables and functions, and this PR would have added 6 more, a new API is
introduced to cut down on replication and present a cleaner interface.
For the global (non-set-specific) API, the old entry points still exist
for backward compatibility, but are phrased internally in terms of the
following.

    // Resource type for IO resolver
    enum TResourceType {
        EResSampler,
        EResTexture,
        EResImage,
        EResUbo,
        EResSsbo,
        EResUav,
        EResCount
    };

Methods on TShader:

    void setShiftBinding(TResourceType res, unsigned int base);
    void setShiftBindingForSet(TResourceType res, unsigned int set, unsigned int base);

The first method replaces the 6 prior entry points of various spellings, which
exist now in depreciated form.  The second provides per-resource-set functionality.
Both accept an enum from the list above.

From the command line, the existing options can accept either a single shift value as
before, or a series of 1 or more [set offset] pairs.  Both can be provided, as in:

    ... --stb 20 --stb 2 25 3 30 ...

which will use the offset 20 for anything except descriptor set 2 (which uses 25) and
3 (which uses 30).

Also added known-good mechanism to fetch latest validated spirv-tools.
Also added -Od and -Os to disable optimizer and optimize for size.

Fetching spirv-tools is optional for both glsl and hlsl. Legalization
of hlsl is done by default if spirv-opt is present at cmake time.
Optimization for glsl is currently done through the option -Os.

Legalization testing is currently only done on four existing shaders.
A separate baseLegalResults directory holds those results. All previous
testing is done with the optimizer disabled.

Remapper errors are generally fatal: there has been some unexpected situation while
parsing the SPV binary, and there is no reasonable way to carry on.  The
errorHandler() function is called in this case, which by default exits, but
it is possible to submit a handler which does not.  In that case the remapper would
carry on in a bad state.

This change ensures a graceful termination of the remap() function.

While a try {} catch {} construct would be the ideal and safe way to do this,
that's off limits for certain environments, so this tries to do the same thing
with explicit code, to catch all the bailout paths.

Fixes #1045.

Fix #1019.

--resource-set-binding has a mode which allows per-register assignments of
bindings and descriptor sets on the command line, and another accepting a
single descriptor set value to assign to all variables.

The former worked, but the latter would crash when assigning the values.
This fixes it, and makes the former case a bit more robust against premature
termination of the pre-register values, which must come in (regname,set,binding)
triples.

This also allows the form "--resource-set-binding stage setnum", which was
mentioned in the usage message, but did not parse.

The operation of the per-register form of this option is unchanged.

The multithreaded outputs in particular can be troublesome when searching.

Works for both GLSL and HLSL.
Fixes #87.

Also, provides an option to auto-assign locations.
Existing tests use this option, to avoid the error message,
however, it is not fully implemented yet.

Adds --hlsl-iomap option to perform IO mapping in HLSL register space.

--shift-cbuffer-binding is now a synonym for --shift-ubo-binding.

The idea way to do this seems to be passing in a dedicated IO resolver, but
that would require more intrusive restructuring, so maybe best for its
own PR.

The TDefaultHlslIoResolver class and the former TDefaultIoResolver class
share quite a bit of mechanism in a common base class.

TODO: tbuffers are landing in the wrong register class, which needs some
investigation.  They're either wrong upstream, or the detection in the
resolver is wrong.

Corresponds to the EShMsgHlslOffsets flag in messages.
Works for both GLSL and HLSL.

Adding a test for this also uncovered an extraneous \r in the runtests script,
fixed now.

Fixes issue #610. Also provides a testing option to keep uncalled functions.

Recently added entry point renaming file referred to
test source file hlsl.entry.rename.frag via relative directory.

Change it to be consistent with other tests: assume test
sources are in the current directory.

Use "--source-entrypoint name" on the command line, or the
TShader::setSourceEntryPoint(char*) API.

When the name given to the above interfaces is detected in the
shader source, it will be renamed to the entry point name supplied
to the -e option or the TShader::setEntryPoint() method.

- Add new queries: TProgram::getUniformTType and getUniformBlockTType,
  which return a const TType*, or nullptr on a bad index.  These are valid for
  any source language.

- Interface name for HLSL cbuffers is taken from the (only) available declaration name,
  whereas before it was always an empty string, which caused some troubles with reflection
  mapping them all to the same index slot.  This also makes it appear in the SPIR-V binary
  instead of an empty string.

- Print the binding as part of the reflection textual dump.

- TType::clone becomes const.  Needed to call it from a const method, and anyway it doesn't
  change the object it's called on.

- Because the TObjectReflection constructor is called with a TType *reference* (not pointer)
  so that it's guaranteed to pass in a type, and the "badReflection" value should use a nullptr
  there, that now has a dedicated static method to obtain the bad value.  It uses a private
  constructor, so external users can't create one with a nullptr type.