Implement GL_EXT_scalar_block_layout

Test/spv.scalarlayoutfloat16.frag

@@ -0,0 +1,31 @@
+#version 450 core
+
+#extension GL_EXT_shader_16bit_storage: enable
+#extension GL_EXT_scalar_block_layout : enable
+
+// Block memory layout
+struct S
+{
+    float16_t      a;   // offset 0
+    f16vec2        b;   // offset 2
+    double         c;   // offset 8
+    float16_t      d;   // offset 16
+    f16vec3        e;   // offset 18
+    float16_t      f;   // offset 24
+    // size = 26, align = 8
+};
+
+layout(column_major, scalar) uniform B1
+{
+    float16_t      a;     // offset = 0
+    f16vec2        b;     // offset = 2
+    f16vec3        c;     // offset = 6
+    float16_t      d[2];  // offset = 12 stride = 2
+    float16_t      g;     // offset = 16
+    S              h;     // offset = 24 (aligned to multiple of 8)
+    S              i[2];  // offset = 56 (aligned to multiple of 8) stride = 32
+};
+
+void main()
+{
+}