[Build] Fix a conflict resolution mistake.

Apparently I accidentally removed a `]` while resolving a conflict in
`build_script_invocation.py.`

rdar://123503470

Author: al45tair

utils/swift_build_support/swift_build_support/build_script_invocation.py

@@ -518,6 +518,7 @@ def convert_to_impl_arguments(self):
             impl_args += [
                 "--extra-dsymutil-args=%s" % ' '.join(
                     shlex.quote(opt) for opt in args.extra_dsymutil_args)
+            ]
 
         if args.musl_path:
             impl_args += [