Revert "Intel(R) Memory Protection Extensions (Intel(R) MPX) support."

This reverts commit rL280668 because the register tests fail on i386
Linux.

I investigated a little bit what causes the failure - there are missing
registers when running 'register read -a'.
This is the output I got at the bottom:
"""
...
Memory Protection Extensions:
      bnd0 = {0x0000000000000000 0x0000000000000000}
      bnd1 = {0x0000000000000000 0x0000000000000000}
      bnd2 = {0x0000000000000000 0x0000000000000000}
      bnd3 = {0x0000000000000000 0x0000000000000000}

unknown:
2 registers were unavailable.
"""

Also looking at the packets exchanged between the client and server:
"""
...
history[308] tid=0x7338 <  19> send packet: $qRegisterInfo4a#d7
history[309] tid=0x7338 < 130> read packet:
$name:bnd0;bitsize:128;offset:1032;encoding:vector;format:vector-uint64;set:Memory
Protection Extensions;ehframe:101;dwarf:101;#48
history[310] tid=0x7338 <  19> send packet: $qRegisterInfo4b#d8
history[311] tid=0x7338 < 130> read packet:
$name:bnd1;bitsize:128;offset:1048;encoding:vector;format:vector-uint64;set:Memory
Protection Extensions;ehframe:102;dwarf:102;#52
history[312] tid=0x7338 <  19> send packet: $qRegisterInfo4c#d9
history[313] tid=0x7338 < 130> read packet:
$name:bnd2;bitsize:128;offset:1064;encoding:vector;format:vector-uint64;set:Memory
Protection Extensions;ehframe:103;dwarf:103;#53
history[314] tid=0x7338 <  19> send packet: $qRegisterInfo4d#da
history[315] tid=0x7338 < 130> read packet:
$name:bnd3;bitsize:128;offset:1080;encoding:vector;format:vector-uint64;set:Memory
Protection Extensions;ehframe:104;dwarf:104;#54
history[316] tid=0x7338 <  19> send packet: $qRegisterInfo4e#db
history[317] tid=0x7338 <  76> read packet:
$name:bndcfgu;bitsize:64;offset:1096;encoding:vector;format:vector-uint8;#99
history[318] tid=0x7338 <  19> send packet: $qRegisterInfo4f#dc
history[319] tid=0x7338 <  78> read packet:
$name:bndstatus;bitsize:64;offset:1104;encoding:vector;format:vector-uint8;#8e
...
"""

The bndcfgu and bndstatus registers don't have the 'Memory Protections
Extension' set. I looked at the code and it seems that that is set
correctly.

So I'm not sure what's the problem or where does it come from.

Also there is a second failure related to something like this in the
tests:
"""
registerSet.GetName().lower()
"""

For some reason the registerSet.GetName() returns None.

llvm-svn: 280703