[PATCH] [x32] Fix segmented stacks support

[Rafael Ávila de Espíndola]

The only thing I know is using segmented stacks with LLVM is rust, and even that just as a stack probe while we add proper probe support.

In other words, this LGTM since it is pretty clear it doesn't change old behavior :-)

================
Comment at: lib/Target/X86/X86ISelLowering.cpp:18353
@@ +18352,3 @@
+  const unsigned TlsReg = Is64Bit ? X86::FS : X86::GS;
+  const unsigned TlsOffset = IsLP64 ? 0x70 :
+                         Is64Bit ? 0x40 :
----------------
Please clang-format this.

http://reviews.llvm.org/D5245