Update ExecutionTests source so that it works when converted into HLK tests (microsoft#7765)

Currently, the contents of HLSLExec is copied (with some modifications)
into an internal repo and used to build the HLK tests.

Recent changes have broken this due to differences in build environments
/ expected includes. Longer term we should rationalize this (see microsoft#7586
and microsoft#7410), but for now some targeted changes should allow things to
work again.

Author: damyanp

tools/clang/unittests/HLSLExec/TableParameterHandler.cpp

@@ -1,5 +1,4 @@
 #include "TableParameterHandler.h"
-#include "dxc/Test/HlslTestUtils.h"
 
 TableParameterHandler::TableParameterHandler(TableParameter *pTable,
                                              size_t size)

tools/clang/unittests/HLSLExec/TableParameterHandler.h

@@ -1,17 +1,13 @@
 #ifndef TABLE_PARAMETER_HANDLER_H
 #define TABLE_PARAMETER_HANDLER_H
 
-#include <Verify.h>
-#include <WexString.h>
-#include <WexTestClass.h>
-#include <memory>
-#include <string>
-#include <vector>
-#include <wchar.h>
-#include <windows.h> // For LPCWSTR
-
-#include "dxc/Support/Global.h" // For DXASSERT_ARGS
-#include "dxc/Test/HlslTestUtils.h"
+#include <windows.h>
+#ifdef _HLK_CONF
+#include "DxilConfTestUtils.h"
+#else
+#include "HlslTestUtils.h"
+#include "dxc/Support/Global.h"
+#endif
 
 // Parameter representation for taef data-driven tests
 struct TableParameter {