PGO: create metadata for switch only if it has more than one targets.

When all cases of a switch statement are dead, the weights vector only has one
element, and we will get an ssertion failure when calling createBranchWeights.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165759 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed