Use conforming preprocessor with modern MSVC

https://learn.microsoft.com/en-us/cpp/preprocessor/preprocessor-experimental-overview

libraries/get-windows-libs.bat

@@ -4,7 +4,7 @@ cd /D "%~dp0"
 
 rem **SVN revision to checkout for windows-libs or windows-libs-amd64**
 rem **Update this line when you commit an update to windows-libs or windows-libs-amd64**
-set "svnrev=28267"
+set "svnrev=28268"
 
 if "%1" == "--amd64" (
     set "LIBS_PATH=win64"

libraries/source/spidermonkey/build.sh

@@ -205,12 +205,6 @@ if [ "${OS}" = "Windows_NT" ]; then
 		cd "${FOLDER}"/build-release/dist/include
 		rm -f mozzconf.h zconf.h zlib.h
 	)
-
-	# SpiderMonkey can be linked/included in projects built with MSVC, however, since clang is now the only
-	# supported compiler on Windows, the codebase has accumulated some divergences with MSVC.
-	# Upstream tries on a best-effort basis to keep the SM headers MSVC-compatible.
-	patch -d "${FOLDER}"/build-debug/dist/include -p1 <patches/FixHeadersForMSVC.diff
-	patch -d "${FOLDER}"/build-release/dist/include -p1 <patches/FixHeadersForMSVC.diff
 fi
 
 # js-config.h is different for debug and release builds, so we need different include directories for both

libraries/source/spidermonkey/patches/FixHeadersForMSVC.diff

@@ -1,38 +0,0 @@
-diff --git a/jspubtd.h b/jspubtd.h
-index 97de470db..1507b6b6b 100644
---- a/jspubtd.h
-+++ b/jspubtd.h
-@@ -51,6 +51,11 @@ enum JSType {
- enum JSProtoKey {
- #define PROTOKEY_AND_INITIALIZER(name, clasp) JSProto_##name,
-   JS_FOR_EACH_PROTOTYPE(PROTOKEY_AND_INITIALIZER)
-+// Workaround MSVC's __VA_ARGS__ quirk, until bug 1768634 is solved
-+// https://bugzilla.mozilla.org/show_bug.cgi?id=1768634
-+#ifdef _MSC_VER
-+  ,
-+#endif
- #undef PROTOKEY_AND_INITIALIZER
-       JSProto_LIMIT
- };
-
-diff --git a/mozilla/Result.h b/mozilla/Result.h
-index cc4f87826..0e763a300 100644
---- a/mozilla/Result.h
-+++ b/mozilla/Result.h
-@@ -212,10 +212,16 @@ using UnsignedIntType = std::conditional_t<
-  */
- template <typename V, typename E>
- class ResultImplementation<V, E, PackingStrategy::LowBitTagIsError> {
-+// These assertions fail with MSVC 14.1. Similar bugs:
-+// https://bugzilla.mozilla.org/show_bug.cgi?id=1778246
-+// https://bugzilla.mozilla.org/show_bug.cgi?id=1778247
-+// TODO: test with recent MSVC before reporting a bug
-+#ifndef _MSC_VER
-   static_assert(std::is_trivially_copyable_v<V> &&
-                 std::is_trivially_destructible_v<V>);
-   static_assert(std::is_trivially_copyable_v<E> &&
-                 std::is_trivially_destructible_v<E>);
-+#endif
- 
-   static constexpr size_t kRequiredSize = std::max(sizeof(V), sizeof(E));
-