Modify testing to only record validation pass/fail

* Changed unit tests to only record known the validation pass/fail
status
 * errors are output as part of the failure message if the result is
 unexpected
 * can turn off validation for each test individually
* Moved some SPV_KHR_vulkan_memory_model tests to be compiled for Vulkan
1.1

gtests/Link.FromFile.cpp

@@ -50,6 +50,7 @@ TEST_P(LinkTest, FromFile)
     const size_t fileCount = fileNames.size();
     const EShMessages controls = DeriveOptions(Source::GLSL, Semantics::OpenGL, Target::AST);
     GlslangResult result;
+    result.validationResult = true;
 
     // Compile each input shader file.
     std::vector<std::unique_ptr<glslang::TShader>> shaders;