Add PR_SET_VMA and PR_SET_VMA_ANON_NAME to <sys/prctl.h>.

We've copied & pasted these to too many places. And if we're going to
have another go at upstreaming these, that's probably yet another reason
to have the *values* in just one place. (Even if upstream wants different
names, we'll likely keep the legacy names around for a while for source
compatibility.)

Bug: http://b/111903542
Test: ran tests
Change-Id: I8ccc557453d69530e5b74f865cbe0b458c84e3ba
diff --git a/linker/linker_block_allocator.cpp b/linker/linker_block_allocator.cpp
index abb1ebd..dca944e 100644
--- a/linker/linker_block_allocator.cpp
+++ b/linker/linker_block_allocator.cpp
@@ -30,10 +30,9 @@
 #include <inttypes.h>
 #include <string.h>
 #include <sys/mman.h>
+#include <sys/prctl.h>
 #include <unistd.h>
 
-#include "private/bionic_prctl.h"
-
 // the multiplier should be power of 2
 static constexpr size_t round_up(size_t size, size_t multiplier) {
   return (size + (multiplier - 1)) & ~(multiplier-1);