dump hash stats
Add murmurhash3

I use Austin Appleby's Public Domain Murmur3 reference code.
I don't own that code. Murmur hash is available from
http://code.google.com/p/smhasher/wiki/MurmurHash

gcc/:

2013-04-18  Andi Kleen <ak@linux.intel.com>

	* murmurhash3.h: New file.
Use murmurhash3 for pointer map hashing

For a large LTO test case The previous pointer hash change brought
the collision rate for the WPA gimple type hash table from 90% to
70. This patch uses the well known murmur3 to improve it further
to 64%.

XXX numbers are outdated

gcc/:

2013-04-18  Andi Kleen <ak@linux.intel.com>

	* Makefile.in (tree.o): Add murmurhash3.h dependency.
	* tree.c (tree_map_base_hash): Use murmurhash3.

Conflicts:
	gcc/Makefile.in
	gcc/tree.c
Add murmurhash2a

Used in the next patch.

I use Austin Appleby's Public Domain Murmur2A reference code.
I don't own that code. Murmur hash is available from
http://code.google.com/p/smhasher/wiki/MurmurHash

gcc/:

2013-04-18  Andi Kleen <ak@linux.intel.com>

	* murmurhash.h: New file
Use murmurhash2A for LTO type hashing
Use murmur3 for hash-table pointer hash
add basic spooky
use spooky for lto type hash
convert tree.c to new hash
use incremential hash for lto streamer
fixup! use incremential hash for lto streamer
fixup! dump hash stats
fixup! use incremential hash for lto streamer