Don't pass through to DXIL.dll in DxcCreateInstance for CLSID_DxcValidator (#7409)

This change removes the code meant to pass through to DXIL.dll when
creating a CLSID_DxcValidator object with DxcCreateInstance.

Since the internal validator is now the default, and it will sign
shaders, there is no reason to pass through to DXIL.dll when using
DxcCreateInstance on DxCompiler.dll.

Testing will come with planned work to include the ability to globally
override the default validator to external.

Author: tex3d

tools/clang/tools/dxcompiler/dxcapi.cpp

@@ -87,11 +87,7 @@ static HRESULT ThreadMallocDxcCreateInstance(REFCLSID rclsid, REFIID riid,
   } else if (IsEqualCLSID(rclsid, CLSID_DxcUtils)) {
     hr = CreateDxcUtils(riid, ppv);
   } else if (IsEqualCLSID(rclsid, CLSID_DxcValidator)) {
-    if (DxilLibIsEnabled()) {
-      hr = DxilLibCreateInstance(rclsid, riid, (IUnknown **)ppv);
-    } else {
-      hr = CreateDxcValidator(riid, ppv);
-    }
+    hr = CreateDxcValidator(riid, ppv);
   } else if (IsEqualCLSID(rclsid, CLSID_DxcAssembler)) {
     hr = CreateDxcAssembler(riid, ppv);
   } else if (IsEqualCLSID(rclsid, CLSID_DxcOptimizer)) {