Darwin, libsanitizer : Support libsanitizer for x86_64-darwin20.

The sanitizer is supported for at least x86_64 and Darwin20.

libsanitizer/ChangeLog:

	* configure.tgt: Allow x86_64 Darwin2x.

(cherry picked from commit 93f1186)

libsanitizer/configure.tgt

@@ -60,7 +60,7 @@ case "${target}" in
 		TSAN_TARGET_DEPENDENT_OBJECTS=tsan_rtl_aarch64.lo
 	fi
 	;;
-  x86_64-*-darwin1[1-9]* | i?86-*-darwin1[1-9]*)
+  x86_64-*-darwin2* | x86_64-*-darwin1[2-9]* | i?86-*-darwin1[1-9]*)
 	TSAN_SUPPORTED=no
 	EXTRA_CXXFLAGS+="-Wl,-undefined,dynamic_lookup"
 	;;