Apply SANITIZE_TARGET=safe-stack to 64 bit targets only.

Bug: 27729263
Change-Id: I214a9f40b94f6e6716aca05be774f014e62f73e8
diff --git a/core/config_sanitizers.mk b/core/config_sanitizers.mk
index 41f0680..9602626 100644
--- a/core/config_sanitizers.mk
+++ b/core/config_sanitizers.mk
@@ -75,6 +75,12 @@
   endif
 endif
 
+ifneq ($(filter safe-stack,$(my_sanitize)),)
+  ifeq ($(my_32_64_bit_suffix),32)
+    my_sanitize := $(filter-out safe-stack,$(my_sanitize))
+  endif
+endif
+
 # Undefined symbols can occur if a non-sanitized library links
 # sanitized static libraries. That's OK, because the executable
 # always depends on the ASan runtime library, which defines these