[Profile] Fix builtin_expect lowering bug

The lowerer wrongly assumes the ICMP instruction 
 1) always has a constant operand;
 2) the operand has value 0.

It also assumes the expected value can only be one, thus
other values other than one will be considered 'zero'.

This leads to wrong profile annotation when other integer values
are used other than 0, 1 in the comparison or in the expect intrinsic.

Also missing is handling of equal predicate.

This patch fixes all the above problems.

Differential Revision: http://reviews.llvm.org/D33757

llvm-svn: 304453