[CMake] Fix error: invalid value 'address -sanitize=undefined' in '-sanitize='

Currently, when having both ASan and UBSan enabled, the compiler is
passed "-sanitize=address -sanitize=undefined" which results in error:
invalid value 'address -sanitize=undefined' in '-sanitize='. Pass the
two flags separately to fix the issue.

Author: JDevlieghere

cmake/modules/AddSwift.cmake

@@ -96,7 +96,7 @@ function(_add_host_variant_swift_sanitizer_flags target)
       # Not supported
     elseif(LLVM_USE_SANITIZER STREQUAL "Address;Undefined" OR
            LLVM_USE_SANITIZER STREQUAL "Undefined;Address")
-      set(_Swift_SANITIZER_FLAGS "-sanitize=address -sanitize=undefined")
+      set(_Swift_SANITIZER_FLAGS "-sanitize=address" "-sanitize=undefined")
     elseif(LLVM_USE_SANITIZER STREQUAL "Leaks")
       # Not supported
     else()