Disable -Werror for QNX's compiler

The compiler is mostly GCC in disguise, but the libraries are not. Since
the toolchain is not open, it's difficult to fix issues in it.

Task-number: QTBUG-59671
Task-number: QTBUG-59672
Change-Id: Id92f4a61915b49ddaee6fffd14aea2639153f073
Reviewed-by: Jake Petroules <jake.petroules@qt.io>

mkspecs/features/qt_common.prf

@@ -88,7 +88,7 @@ warnings_are_errors:warning_clean {
             #      (NULL in C++ is usually a literal 0)
             QMAKE_CXXFLAGS_WARN_ON += -Werror -ww177,1224,1478,1881 $$WERROR
         }
-    } else:gcc:!clang:!intel_icc {
+    } else:gcc:!clang:!intel_icc:!rim_qcc {
         # GCC 4.6-4.9, 5.x, ...
         ver = $${QT_GCC_MAJOR_VERSION}.$${QT_GCC_MINOR_VERSION}
         contains(ver, "(4\\.[6789]|[5-9]\\..)") {

mkspecs/features/qt_module_headers.prf

@@ -180,7 +180,7 @@ headersclean:!internal_module {
                  -Dforeach=public: \
                  -Dforever=public:
 
-    gcc {
+    gcc:!rim_qcc {
         # Turn on some extra warnings not found in -Wall -Wextra.
         # Common to GCC, Clang and ICC (and other compilers that masquerade as GCC):
         hcleanFLAGS = -Wall -Wextra -Werror \