Implement GL_EXT_shader_16bit_storage and GL_EXT_shader_8bit_storage extensions.

These introduce limited support for 8/16-bit types such that they can only be accessed in buffer memory and converted to/from 32-bit types.

Contributed from Khronos-internal work.

glslang/Include/Types.h

@@ -1472,6 +1472,16 @@ public:
         return contains([](const TType* t) { return t->isArray() && t->arraySizes->isOuterSpecialization(); } );
     }
 
+    virtual bool contains16BitInt() const
+    {
+        return containsBasicType(EbtInt16) || containsBasicType(EbtUint16);
+    }
+
+    virtual bool contains8BitInt() const
+    {
+        return containsBasicType(EbtInt8) || containsBasicType(EbtUint8);
+    }
+
     // Array editing methods.  Array descriptors can be shared across
     // type instances.  This allows all uses of the same array
     // to be updated at once.  E.g., all nodes can be explicitly sized

glslang/Include/revision.h

@@ -1,3 +1,3 @@
 // This header is generated by the make-revision script.
 
-#define GLSLANG_PATCH_LEVEL 2796
+#define GLSLANG_PATCH_LEVEL 2797