[PATCH] [PowerPC] Fix unwind info with dynamic stack realignment

[Will Schmidt]

This looks straightforward..  A cosmetic comment inline, but I've no issues with the patch.
I defer to Uli/Hal for their approval.

================
Comment at: lib/Target/PowerPC/PPCFrameLowering.cpp:737
@@ +736,3 @@
+      // terms of BP, because it's not at a fixed offset from SP.
+      // Otherwise, we could define it in terms of either BP or SP, but BP is
+      // easier because the offset is always zero.
----------------
s/Otherwise, we/We/

================
Comment at: lib/Target/PowerPC/PPCFrameLowering.cpp:739
@@ +738,3 @@
+      // easier because the offset is always zero.
+      unsigned Reg = MRI->getDwarfRegNum(BPReg, true);
+      CFIIndex = MMI.addFrameInst(
----------------
I'd be tempted to use something other than 'Reg' here, but looks like many other callers to this function also use Reg, so.. just a passing thought, no objection.  :-)

http://reviews.llvm.org/D6410