Move size and alignment information of regclass to TargetRegisterInfo

1. RegisterClass::getSize() is split into two functions:
   - TargetRegisterInfo::getRegSizeInBits(const TargetRegisterClass &RC) const;
   - TargetRegisterInfo::getSpillSize(const TargetRegisterClass &RC) const;
2. RegisterClass::getAlignment() is replaced by:
   - TargetRegisterInfo::getSpillAlignment(const TargetRegisterClass &RC) const;

This will allow making those values depend on subtarget features in the
future.

Differential Revision: https://reviews.llvm.org/D31783

llvm-svn: 301221
diff --git a/llvm/lib/CodeGen/VirtRegMap.cpp b/llvm/lib/CodeGen/VirtRegMap.cpp
index c894601..d10ca1a 100644
--- a/llvm/lib/CodeGen/VirtRegMap.cpp
+++ b/llvm/lib/CodeGen/VirtRegMap.cpp
@@ -73,8 +73,9 @@
 }
 
 unsigned VirtRegMap::createSpillSlot(const TargetRegisterClass *RC) {
-  int SS = MF->getFrameInfo().CreateSpillStackObject(RC->getSize(),
-                                                     RC->getAlignment());
+  unsigned Size = TRI->getSpillSize(*RC);
+  unsigned Align = TRI->getSpillAlignment(*RC);
+  int SS = MF->getFrameInfo().CreateSpillStackObject(Size, Align);
   ++NumSpillSlots;
   return SS;
 }