remove more pragma instances of GCC system_header

Use "#pragma GCC diagnostic ignored" instead which does not prevent
generation of dependencies.

Change-Id: Ic9034f20ef71c1ee6e5363b73c831142c2813d20

include/tools/inetmime.hxx

@@ -410,11 +410,6 @@ public:
     static OUString decodeHeaderFieldBody(HeaderFieldType eType,
                                            const OString& rBody);
 
-// #i70651#: Prevent warnings on Mac OS X.
-#ifdef MACOSX
-#pragma GCC system_header
-#endif
-
     /** Get the UTF-32 character at the head of a UTF-16 encoded string.
 
         @param rBegin  Points to the start of the UTF-16 encoded string, must

sdext/source/pdfimport/xpdfwrapper/pdfioutdev_gpl.hxx

@@ -23,7 +23,10 @@
 #include <sal/types.h>
 
 #if defined __GNUC__
-#pragma GCC system_header
+#if HAVE_GCC_PRAGMA_DIAGNOSTIC_MODIFY
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wunused-parameter"
+#endif
 #elif defined __SUNPRO_CC
 #pragma disable_warn
 #elif defined _MSC_VER
@@ -39,7 +42,11 @@
 #include "GlobalParams.h"
 #include "PDFDoc.h"
 
-#if defined __SUNPRO_CC
+#if defined __GNUC__
+#if HAVE_GCC_PRAGMA_DIAGNOSTIC_MODIFY
+# pragma GCC diagnostic pop
+#endif
+#elif defined __SUNPRO_CC
 #pragma enable_warn
 #elif defined _MSC_VER
 #pragma warning(pop)