Add a Windows no-op impl of BORINGSSL_self_test

Change-Id: Id5b5b639023d30a8ebd763d02e1787fbf9d79288
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/46245
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>

crypto/fipsmodule/self_check/self_check.c

@@ -38,8 +38,14 @@
 
 
 // MSVC wants to put a NUL byte at the end of non-char arrays and so cannot
-// compile this.
-#if !defined(_MSC_VER)
+// compile the real logic.
+#if defined(_MSC_VER)
+
+int BORINGSSL_self_test(void) {
+  return 0;
+}
+
+#else
 
 #if defined(BORINGSSL_FIPS) && defined(OPENSSL_ANDROID)
 // FIPS builds on Android will test for flag files, named after the module hash,