Pass variant triple to refactor invocations in tests

This fixes 71 tests for Android on Windows that previously failed with:
error: unable to load standard library for target 'x86_64-unknown-windows-msvc'

Author: weliveindetail

test/refactoring/lit.local.cfg

@@ -1,2 +1,2 @@
-config.substitutions.append((r'%refactor-check-compiles', f'{config.python} {config.refactor_check_compiles} -swift-refactor {config.swift_refactor} -swift-frontend {config.swift_frontend} -temp-dir %t {config.resource_dir_opt}'))
-config.substitutions.append((r'%refactor', f'{config.swift_refactor} {config.resource_dir_opt}'))
+config.substitutions.append((r'%refactor-check-compiles', f'{config.python} {config.refactor_check_compiles} -swift-refactor {config.swift_refactor} -swift-frontend {config.swift_frontend} -temp-dir %t {config.resource_dir_opt} -target {config.variant_triple}'))
+config.substitutions.append((r'%refactor', f'{config.swift_refactor} {config.resource_dir_opt} -target {config.variant_triple}'))