For Clang -fsanitize=vptr use -fvisibility-ms-compat, not -fvisibility=hidden

...same as f0aa1a78

Change-Id: I35c1e6928dd4b29ef0ab448a181a5af7fb0640ab

external/libfreehand/UnpackedTarball_libfreehand.mk

@@ -11,4 +11,14 @@ $(eval $(call gb_UnpackedTarball_UnpackedTarball,libfreehand))
 
 $(eval $(call gb_UnpackedTarball_set_tarball,libfreehand,$(FREEHAND_TARBALL)))
 
+$(eval $(call gb_UnpackedTarball_set_patchlevel,libfreehand,0))
+
+ifeq ($(COM_GCC_IS_CLANG),TRUE)
+ifneq ($(filter -fsanitize=%,$(CC)),)
+$(eval $(call gb_UnpackedTarball_add_patches,libfreehand, \
+    external/libfreehand/ubsan-visibility.patch \
+))
+endif
+endif
+
 # vim: set noet sw=4 ts=4:

external/libfreehand/ubsan-visibility.patch

+--- configure
++++ configure
+@@ -18369,7 +18369,7 @@
+         { $as_echo "$as_me:${as_lineno-$LINENO}: checking for -fvisibility=hidden compiler flag" >&5
+ $as_echo_n "checking for -fvisibility=hidden compiler flag... " >&6; }
+         saved_CXXFLAGS="$CXXFLAGS"
+-        CXXFLAGS="$CXXFLAGS -fvisibility=hidden"
++        CXXFLAGS="$CXXFLAGS -fvisibility-ms-compat"
+         cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+ /* end confdefs.h.  */
+