Add test for input I/O blocks in fragment.

reference/shaders-hlsl/frag/io-block.frag

@@ -0,0 +1,28 @@
+static float4 FragColor;
+
+struct VertexOut
+{
+    float4 a : TEXCOORD1;
+    float4 b : TEXCOORD2;
+};
+
+static VertexOut _12;
+
+struct SPIRV_Cross_Output
+{
+    float4 FragColor : SV_Target0;
+};
+
+void frag_main()
+{
+    FragColor = _12.a + _12.b;
+}
+
+SPIRV_Cross_Output main(in VertexOut stage_input_12)
+{
+    _12 = stage_input_12;
+    frag_main();
+    SPIRV_Cross_Output stage_output;
+    stage_output.FragColor = FragColor;
+    return stage_output;
+}

shaders-hlsl/frag/io-block.frag

@@ -0,0 +1,16 @@
+#version 310 es
+#extension GL_EXT_shader_io_blocks : require
+precision mediump float;
+
+layout(location = 1) in VertexOut
+{
+	vec4 a;
+	vec4 b;
+};
+
+layout(location = 0) out vec4 FragColor;
+
+void main()
+{
+	FragColor = a + b;
+}