HLSL: Plumb in HLSL parse context and keywords, and most basic HLSL parser and test.

Test/baseResults/hlsl.frag.out

@@ -0,0 +1,21 @@
+hlsl.frag
+
+Linked fragment stage:
+
+
+// Module Version 10000
+// Generated by (magic number): 80001
+// Id's are bound by 6
+
+                              Capability Shader
+               1:             ExtInstImport  "GLSL.std.450"
+                              MemoryModel Logical GLSL450
+                              EntryPoint Fragment 4  "PixelShaderFunction"
+                              ExecutionMode 4 OriginUpperLeft
+                              Source HLSL 100
+                              Name 4  "PixelShaderFunction"
+               2:             TypeVoid
+               3:             TypeFunction 2
+4(PixelShaderFunction):           2 Function None 3
+               5:             Label
+                              FunctionEnd