Modify malloc common function pointers.

Instead of every function being its own atomic, have a single
pointer that can be used to flip all pointers at once. This avoid cases
where the set of pointers can be in an partial switched state.

Also fix a few inconsistent naming of functions in the file.

Test: Ran unit tests (malloc debug, malloc hooks, perfetto).
Change-Id: I3f66da395414586a3fa87874d80dcdf5f702ed39
Merged-In: I3f66da395414586a3fa87874d80dcdf5f702ed39
(cherry picked from commit 77184aedaf973c6e81accfc737f4fc362dad31ac)
diff --git a/libc/private/bionic_malloc_dispatch.h b/libc/private/bionic_malloc_dispatch.h
index f15b72c..0dce03d 100644
--- a/libc/private/bionic_malloc_dispatch.h
+++ b/libc/private/bionic_malloc_dispatch.h
@@ -31,7 +31,6 @@
 
 #include <stddef.h>
 #include <stdint.h>
-#include <stdatomic.h>
 #include <private/bionic_config.h>
 
 // Entry in malloc dispatch table.
@@ -55,25 +54,25 @@
 #endif
 
 struct MallocDispatch {
-  _Atomic MallocCalloc calloc;
-  _Atomic MallocFree free;
-  _Atomic MallocMallinfo mallinfo;
-  _Atomic MallocMalloc malloc;
-  _Atomic MallocMallocUsableSize malloc_usable_size;
-  _Atomic MallocMemalign memalign;
-  _Atomic MallocPosixMemalign posix_memalign;
+  MallocCalloc calloc;
+  MallocFree free;
+  MallocMallinfo mallinfo;
+  MallocMalloc malloc;
+  MallocMallocUsableSize malloc_usable_size;
+  MallocMemalign memalign;
+  MallocPosixMemalign posix_memalign;
 #if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
-  _Atomic MallocPvalloc pvalloc;
+  MallocPvalloc pvalloc;
 #endif
-  _Atomic MallocRealloc realloc;
+  MallocRealloc realloc;
 #if defined(HAVE_DEPRECATED_MALLOC_FUNCS)
-  _Atomic MallocValloc valloc;
+  MallocValloc valloc;
 #endif
-  _Atomic MallocIterate iterate;
-  _Atomic MallocMallocDisable malloc_disable;
-  _Atomic MallocMallocEnable malloc_enable;
-  _Atomic MallocMallopt mallopt;
-  _Atomic MallocAlignedAlloc aligned_alloc;
+  MallocIterate iterate;
+  MallocMallocDisable malloc_disable;
+  MallocMallocEnable malloc_enable;
+  MallocMallopt mallopt;
+  MallocAlignedAlloc aligned_alloc;
 } __attribute__((aligned(32)));
 
 #endif