Implement the extension GL_EXT_spirv_intrinsics

- Add support of SPIR-V execution mode qualifiers.
- Add support of SPIR-V storage class qualifier.
- Add support of SPIR-V decorate qualifiers.
- Add support of SPIR-V type specifier.
- Add support of SPIR-V intruction qualifiers.
- Add support of spirv_by_reference/spirv_literal parameter qualifier.
- Add shader stage macros introduced by this extension.

Test/spv.intrinsicsSpirvInstruction.vert

@@ -0,0 +1,26 @@
+#version 450 core
+
+#extension GL_EXT_spirv_intrinsics: enable
+#extension GL_ARB_gpu_shader_int64: enable
+
+spirv_instruction (extensions = ["SPV_KHR_shader_clock"], capabilities = [5055], id = 5056)
+uvec2 clockRealtime2x32EXT(void);
+
+spirv_instruction (extensions = ["SPV_KHR_shader_clock"], capabilities = [5055], id = 5056)
+int64_t clockRealtimeEXT(void);
+
+spirv_instruction (extensions = ["SPV_AMD_shader_trinary_minmax"], set = "SPV_AMD_shader_trinary_minmax", id = 1)
+vec2 min3(vec2 x, vec2 y, vec2 z);
+
+layout(location = 0) in vec3 vec3In;
+
+layout(location = 0) out uvec2 uvec2Out;
+layout(location = 1) out int64_t i64Out;
+layout(location = 2) out vec2 vec2Out;
+
+void main()
+{
+    uvec2Out = clockRealtime2x32EXT();
+    i64Out = clockRealtimeEXT();
+    vec2Out = min3(vec3In.xy, vec3In.yz, vec3In.zx); 
+}