Add missing include header for llvm7

Change-Id: I4e8afbae543c3d427bae225d9050fc1eddb74314

Author: lwesiers

IGC/Compiler/CodeGenContext.cpp

@@ -23,6 +23,10 @@ SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
 
 ======================= end_copyright_notice ==================================*/
+#include "common/LLVMWarningsPush.hpp"
+#include <llvm/Support/ScaledNumber.h>
+#include "common/LLVMWarningsPop.hpp"
+
 #include "Compiler/CISACodeGen/ComputeShaderCodeGen.hpp"
 #include "Compiler/CISACodeGen/ShaderCodeGen.hpp"
 #include "Compiler/CodeGenPublic.h"