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