HLSL: Fix crash with --resource-set-binding [n] (global form, not per-register form)

--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.

SPV: Decorate parameters

HLSL: Fix #980: flatten opaque initializers to use aliases.

Fix NULL pointer dereference in TParseContext::builtInOpCheck

Address part B of #982: $Global will use std140 instead of HLSL offsets.

From comment about this:
Adjust alignment for HLSL rules
TODO: make this consistent in early phases of code: adjusting this late means inconsistencies with earlier code, which for reflection is an issue.
Until reflection is brought in sync with these adjustments, don't apply to $Global,
which is the most likely to rely on reflection, and least likely to rely
implicit layouts.

HLSL: support global const initializers from non-constant rvalues

Fix StandAlone.cpp compilation warnings

find_first_of returns size_t, was overflowing int.

Semantic test left over from other source languages is removed, since this is permitted by HLSL.
Also, to support the functionality, a targeted test is performed for this case and it is
turned into a EvqGlobal qualifier to create an AST initialization segment when needed.

Constness is now propagated up aggregate chains during initializer construction.  This
handles hierarchical cases such as the distinction between:

    static const float2 a[2] = { { 1, 2 }, { 3, 4} };

vs

    static const float2 a[2] = { { 1, 2 }, { cbuffer_member, 4} };

The first of which can use a first class constant initalization, and the second cannot.

The multithreaded outputs in particular can be troublesome when searching.

HLSL: Translate directive [flatten] and [branch] to SPV control mask.

Implement SPV_KHR_post_depth_coverage

Added support for both extension GL_ARB_post_depth_coverage and GL_EXT_post_depth_coverage.

HLSL: handle type conversion for any/all intrinsics

HLSL allows float/etc types for any/all intrinsics, while the
SPIR-V opcode requires bool.  This adds a simple decomposition
to type convert the argument.  It could get a little more clever
in some of the type cases if it ever had to.

Add option to skip installation

Fix CMake scripts to set the POSITION_INDEPENDENT_CODE property correctly

Fix CMake scripts: The set_property script can be used to set only a single property, so now setting the POSITION_INDEPENDENT_CODE property correctly.