Add no fallback to cxx flags

Jenkinsfile

@@ -6,7 +6,7 @@ def rocmtestnode(variant, name, body) {
             rm -rf build
             mkdir build
             cd build
-            CXX=${compiler} CXXFLAGS='-Werror' cmake -DCMAKE_CXX_FLAGS_DEBUG='-g -fno-omit-frame-pointer -fsanitize=undefined -fno-sanitize-recover=undefined' ${flags} .. 
+            CXX=${compiler} CXXFLAGS='-Werror -Wno-fallback' cmake -DCMAKE_CXX_FLAGS_DEBUG='-g -fno-omit-frame-pointer -fsanitize=undefined -fno-sanitize-recover=undefined' ${flags} .. 
             CTEST_PARALLEL_LEVEL=32 make -j32 all doc check
         """
         echo cmd

cmake/EnableCompilerWarnings.cmake

@@ -77,7 +77,6 @@ else()
                 -Wno-double-promotion
                 -Wno-exit-time-destructors
                 -Wno-extra-semi
-                -Wno-fallback
                 -Wno-float-conversion
                 -Wno-gnu-anonymous-struct
                 -Wno-gnu-zero-variadic-macro-arguments