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

...same as f0aa1a78

Change-Id: Ib02a20677eaaf2930bf3620c4ed2b1c3c098ce00

external/libetonyek/UnpackedTarball_libetonyek.mk

@@ -19,4 +19,12 @@ $(eval $(call gb_UnpackedTarball_add_patches,libetonyek,\
 	external/libetonyek/win_build.patch.1 \
 ))
 
+ifeq ($(COM_GCC_IS_CLANG),TRUE)
+ifneq ($(filter -fsanitize=%,$(CC)),)
+$(eval $(call gb_UnpackedTarball_add_patches,libetonyek, \
+    external/libetonyek/ubsan-visibility.patch \
+))
+endif
+endif
+
 # vim: set noet sw=4 ts=4:

external/libetonyek/ubsan-visibility.patch

+--- configure
++++ configure
+@@ -17443,7 +17443,7 @@
+         { $as_echo "$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.  */
+