deps: V8: cherry-pick 0c8b6e415c30

Original commit message:

    [mac][wasm] Work around MacOS 11.2 code page decommit failures

    MacOS 11.2 refuses to set "no access" permissions on memory that
    we previously used for JIT-compiled code. It is still unclear
    whether this is WAI on the part of the kernel. In the meantime,
    as a workaround, we use madvise(..., MADV_FREE_REUSABLE) instead
    of mprotect(..., NONE) when discarding code pages. This is inspired
    by what Chromium's gin platform does.

    Fixed: v8:11389
    Change-Id: I866586932573b4253002436ae5eee4e0411c45fc
    Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2679688
    Commit-Queue: Jakob Kummerow <[email protected]>
    Commit-Queue: Michael Lippautz <[email protected]>
    Auto-Submit: Jakob Kummerow <[email protected]>
    Reviewed-by: Michael Lippautz <[email protected]>
    Cr-Commit-Position: refs/heads/master@{#72559}

Refs: v8/v8@0c8b6e4
Fixes: nodejs#37061
PR-URL: nodejs#37276
Reviewed-By: Michaël Zasso <[email protected]>
Reviewed-By: Ash Cripps <[email protected]>

common.gypi

@@ -36,7 +36,7 @@
 
     # Reset this number to 0 on major V8 upgrades.
     # Increment by one for each non-official patch applied to deps/v8.
-    'v8_embedder_string': '-node.11',
+    'v8_embedder_string': '-node.12',
 
     ##### V8 defaults for Node.js #####
 

deps/v8/src/base/platform/platform-posix.cc

@@ -415,6 +415,16 @@ bool OS::SetPermissions(void* address, size_t size, MemoryPermission access) {
 
   int prot = GetProtectionFromMemoryPermission(access);
   int ret = mprotect(address, size, prot);
+
+  // MacOS 11.2 on Apple Silicon refuses to switch permissions from
+  // rwx to none. Just use madvise instead.
+#if defined(V8_OS_MACOSX)
+  if (ret != 0 && access == OS::MemoryPermission::kNoAccess) {
+    ret = madvise(address, size, MADV_FREE_REUSABLE);
+    return ret == 0;
+  }
+#endif
+
   if (ret == 0 && access == OS::MemoryPermission::kNoAccess) {
     // This is advisory; ignore errors and continue execution.
     USE(DiscardSystemPages(address, size));