Make LoopInfoBase more generic, in preparation for having MachineLoopInfo.  This involves a small interface change.

llvm-svn: 44348

llvm-svn: 44262

llvm-svn: 41207

llvm-svn: 40603

llvm-svn: 39834

llvm-svn: 39767

llvm-svn: 37966

llvm-svn: 37954

llvm-svn: 37953

llvm-svn: 36994

llvm-svn: 36662

Due to darwin gcc bug, one version of darwin linker coalesces
static const int, which defauts PassID based pass identification.

llvm-svn: 36652

llvm-svn: 36632

llvm-svn: 36031

llvm-svn: 35836

happen to be an entry, in such case, it is not a good idea to
insert new block before entry.

Also fix typo in assertion check.

llvm-svn: 35833

llvm-svn: 35829

llvm-svn: 35825

llvm-svn: 35822

Handle Argument or Undef as an incoming PHI value.

llvm-svn: 35821

llvm-svn: 35820

llvm-svn: 35819

llvm-svn: 35714