GVN-hoist: limit the length of dependent instructions

Limit the number of times the while(1) loop is executed. With this restriction
the number of hoisted instructions does not change in a significant way on the
test-suite.

Differential Revision: https://reviews.llvm.org/D23028

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277651 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed