Upgrade tcmalloc

[pcc]

In my local builds with libc++ and an up-to-date clang I was seeing an unused variable error from tcmalloc. I worked around it with the patch below.

--- tcmalloc/system-alloc.cc.orig       2024-04-11 19:05:57.249351705 -0700
+++ tcmalloc/system-alloc.cc    2024-04-11 19:05:58.672340539 -0700
@@ -652,10 +652,9 @@
           strerror(errno));
       return nullptr;
     }
-    if (int err = munmap(result, size)) {
+    if (munmap(result, size)) {
       Log(kLogWithStack, __FILE__, __LINE__, "munmap() failed (error)",
           strerror(errno));
-      ASSERT(err == 0);
     }
     next_addr = RandomMmapHint(size, alignment, tag);
   }

This seems to have been fixed in upstream tcmalloc by changing the macro used for assertions to always evaluate its argument, so it looks like upgrading tcmalloc will make this problem go away.

[rjogrady]

Thanks for the report!