Bug 931687: Use the -Gw flag on Windows builds for better linker optimizations. r=glandium

js/src/old-configure.in

@@ -750,6 +750,10 @@ case "$target" in
         dnl If nothing, compiler sometimes causes C1041 error.
         CFLAGS="$CFLAGS -FS"
         CXXFLAGS="$CXXFLAGS -FS"
+        dnl VS2013+ supports -Gw for better linker optimizations.
+        dnl http://blogs.msdn.com/b/vcblog/archive/2013/09/11/introducing-gw-compiler-switch.aspx
+        CFLAGS="$CFLAGS -Gw"
+        CXXFLAGS="$CXXFLAGS -Gw"
         # khuey says we can safely ignore MSVC warning C4251
         # MSVC warning C4244 (implicit type conversion may lose data) warns
         # and requires workarounds for perfectly valid code.  Also, GCC/clang

old-configure.in

@@ -1095,6 +1095,10 @@ case "$target" in
         dnl If nothing, compiler sometimes causes C1041 error.
         CFLAGS="$CFLAGS -FS"
         CXXFLAGS="$CXXFLAGS -FS"
+        dnl VS2013+ supports -Gw for better linker optimizations.
+        dnl http://blogs.msdn.com/b/vcblog/archive/2013/09/11/introducing-gw-compiler-switch.aspx
+        CFLAGS="$CFLAGS -Gw"
+        CXXFLAGS="$CXXFLAGS -Gw"
         # khuey says we can safely ignore MSVC warning C4251
         # MSVC warning C4244 (implicit type conversion may lose data) warns
         # and requires workarounds for perfectly valid code.  Also, GCC/clang