Miscellaneous cleanups:

Miscellaneous cleanups:
  * Convert post to pre-increment for for loops
  * Use generic programming more
  * Use new Value::cast* instructions
  * Use new Module, Method, & BasicBlock forwarding methods
  * Use new facilities in STLExtras.h
  * Use new Instruction::isPHINode() method

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96 91177308-0d34-0410-b5e6-96231b3b80d8