SPV: Add SPIRV-Tools validator. This needs the latest SPIR-Tools.

Test/baseResults/hlsl.structbuffer.frag.out

@@ -187,6 +187,10 @@ gl_FragCoord origin is upper left
 0:?     '@entryPointOutput' (layout( location=0) out 4-component vector of float)
 0:?     'pos' (layout( location=0) flat in uint)
 
+error: SPIRV-Tools Validation Errors
+error: OpStore Pointer <id> '43[size]'s type does not match Object <id> '44's type.
+  OpStore %size %44
+
 // Module Version 10000
 // Generated by (magic number): 80007
 // Id's are bound by 96