HLSL: Fix #606: make layout() override register.

Test/baseResults/hlsl.layoutOverride.vert.out

+hlsl.layoutOverride.vert
+Shader version: 500
+0:? Sequence
+0:5  Function Definition: @main( ( temp 4-component vector of float)
+0:5    Function Parameters: 
+0:?     Sequence
+0:6      Branch: Return with expression
+0:6        texture ( temp 4-component vector of float)
+0:6          Construct combined texture-sampler ( temp sampler2D)
+0:6            'tex' (layout( set=2 binding=0) uniform texture2D)
+0:6            'samp' ( uniform sampler)
+0:?           Constant:
+0:?             0.200000
+0:?             0.300000
+0:5  Function Definition: main( ( temp void)
+0:5    Function Parameters: 
+0:?     Sequence
+0:5      move second child to first child ( temp 4-component vector of float)
+0:?         '@entryPointOutput' ( out 4-component vector of float Position)
+0:5        Function Call: @main( ( temp 4-component vector of float)
+0:?   Linker Objects
+0:?     'tex' (layout( set=2 binding=0) uniform texture2D)
+0:?     'samp' ( uniform sampler)
+0:?     '@entryPointOutput' ( out 4-component vector of float Position)
+
+
+Linked vertex stage:
+
+
+Shader version: 500
+0:? Sequence
+0:5  Function Definition: @main( ( temp 4-component vector of float)
+0:5    Function Parameters: 
+0:?     Sequence
+0:6      Branch: Return with expression
+0:6        texture ( temp 4-component vector of float)
+0:6          Construct combined texture-sampler ( temp sampler2D)
+0:6            'tex' (layout( set=2 binding=0) uniform texture2D)
+0:6            'samp' ( uniform sampler)
+0:?           Constant:
+0:?             0.200000
+0:?             0.300000
+0:5  Function Definition: main( ( temp void)
+0:5    Function Parameters: 
+0:?     Sequence
+0:5      move second child to first child ( temp 4-component vector of float)
+0:?         '@entryPointOutput' ( out 4-component vector of float Position)
+0:5        Function Call: @main( ( temp 4-component vector of float)
+0:?   Linker Objects
+0:?     'tex' (layout( set=2 binding=0) uniform texture2D)
+0:?     'samp' ( uniform sampler)
+0:?     '@entryPointOutput' ( out 4-component vector of float Position)
+
+// Module Version 10000
+// Generated by (magic number): 80002
+// Id's are bound by 32
+
+                              Capability Shader
+               1:             ExtInstImport  "GLSL.std.450"
+                              MemoryModel Logical GLSL450
+                              EntryPoint Vertex 4  "main" 30
+                              Source HLSL 500
+                              Name 4  "main"
+                              Name 9  "@main("
+                              Name 13  "tex"
+                              Name 17  "samp"
+                              Name 30  "@entryPointOutput"
+                              Decorate 13(tex) DescriptorSet 2
+                              Decorate 13(tex) Binding 0
+                              Decorate 17(samp) DescriptorSet 0
+                              Decorate 30(@entryPointOutput) BuiltIn Position
+               2:             TypeVoid
+               3:             TypeFunction 2
+               6:             TypeFloat 32
+               7:             TypeVector 6(float) 4
+               8:             TypeFunction 7(fvec4)
+              11:             TypeImage 6(float) 2D sampled format:Unknown
+              12:             TypePointer UniformConstant 11
+         13(tex):     12(ptr) Variable UniformConstant
+              15:             TypeSampler
+              16:             TypePointer UniformConstant 15
+        17(samp):     16(ptr) Variable UniformConstant
+              19:             TypeSampledImage 11
+              21:             TypeVector 6(float) 2
+              22:    6(float) Constant 1045220557
+              23:    6(float) Constant 1050253722
+              24:   21(fvec2) ConstantComposite 22 23
+              25:    6(float) Constant 0
+              29:             TypePointer Output 7(fvec4)
+30(@entryPointOutput):     29(ptr) Variable Output
+         4(main):           2 Function None 3
+               5:             Label
+              31:    7(fvec4) FunctionCall 9(@main()
+                              Store 30(@entryPointOutput) 31
+                              Return
+                              FunctionEnd
+       9(@main():    7(fvec4) Function None 8
+              10:             Label
+              14:          11 Load 13(tex)
+              18:          15 Load 17(samp)
+              20:          19 SampledImage 14 18
+              26:    7(fvec4) ImageSampleExplicitLod 20 24 Lod 25
+                              ReturnValue 26
+                              FunctionEnd

Test/hlsl.layoutOverride.vert

+layout(set=2,binding=0) Texture2D tex : register(t16);
+SamplerState samp;
+
+float4 main() : SV_Position 
+{
+    return tex.Sample(samp, float2(0.2, 0.3));
+}
\ No newline at end of file

gtests/Hlsl.FromFile.cpp

@@ -211,6 +211,7 @@ INSTANTIATE_TEST_CASE_P(
         {"hlsl.intrinsics.promote.down.frag", "main"},
         {"hlsl.intrinsics.promote.outputs.frag", "main"},
         {"hlsl.layout.frag", "main"},
+        {"hlsl.layoutOverride.vert", "main"},
         {"hlsl.load.2dms.dx10.frag", "main"},
         {"hlsl.load.array.dx10.frag", "main"},
         {"hlsl.load.basic.dx10.frag", "main"},

hlsl/hlslParseHelper.cpp

@@ -5856,7 +5856,10 @@ void HlslParseContext::handleRegister(const TSourceLoc& loc, TQualifier& qualifi
     case 'c':
     case 's':
     case 'u':
-        qualifier.layoutBinding = regNumber + subComponent;
+        // if nothing else has set the binding, do so now
+        // (other mechanisms override this one)
+        if (!qualifier.hasBinding())
+            qualifier.layoutBinding = regNumber + subComponent;
 
         // This handles per-register layout sets numbers.  For the global mode which sets
         // every symbol to the same value, see setLinkageLayoutSets().
@@ -5890,7 +5893,9 @@ void HlslParseContext::handleRegister(const TSourceLoc& loc, TQualifier& qualifi
         return true;
     };
 
-    if (spaceDesc) {
+    // if nothing else has set the set, do so now
+    // (other mechanisms override this one)
+    if (spaceDesc && !qualifier.hasSet()) {
         if (! crackSpace()) {
             error(loc, "expected spaceN", "register", "");
             return;