validation-tests: define the MSVC runtime to use

This variable is needed to run the validation test suite on Windows.

Author: compnerd

validation-test/lit.site.cfg.in

@@ -27,10 +27,27 @@ config.variant_suffix = "@VARIANT_SUFFIX@"
 config.variant_sdk = "@VARIANT_SDK@"
 config.swift_test_results_dir = \
     lit_config.params.get("swift_test_results_dir", "@SWIFT_TEST_RESULTS_DIR@")
+
+# --- Darwin Configuration ---
 config.darwin_xcrun_toolchain = "@SWIFT_DARWIN_XCRUN_TOOLCHAIN@"
+
+# --- Android Configuration ---
 config.android_ndk_path = "@SWIFT_ANDROID_NDK_PATH@"
 config.android_ndk_gcc_version = "@SWIFT_ANDROID_NDK_GCC_VERSION@"
 
+# --- Windows MSVC Configuration ---
+config.swift_stdlib_msvc_runtime = None
+if "@SWIFT_STDLIB_MSVC_RUNTIME_LIBRARY@" == "MultiThreaded":
+    config.swift_stdlib_msvc_runtime = 'MT'
+elif "@SWIFT_STDLIB_MSVC_RUNTIME_LIBRARY@" == "MultiThreadedDebug":
+    config.swift_stdlib_msvc_runtime = 'MTd'
+elif "@SWIFT_STDLIB_MSVC_RUNTIME_LIBRARY@" == "MultiThreadedDLL":
+    config.swift_stdlib_msvc_runtime = 'MD'
+elif "@SWIFT_STDLIB_MSVC_RUNTIME_LIBRARY@" == "MultiThreadedDebugDLL":
+    config.swift_stdlib_msvc_runtime = 'MDd'
+else:
+    assert(False)
+
 config.coverage_mode = "@SWIFT_ANALYZE_CODE_COVERAGE@"
 config.lldb_build_root = "@LLDB_BUILD_DIR@"