autoconf: Add PLUTO_FOUND flag

This fixes llvm.org/PR12250.

Contributed-by: Sam Novak <snovak@uwsp.edu>

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@204167 91177308-0d34-0410-b5e6-96231b3b80d8
Dependences: Further reduce the allowed compile time

llvm.org/PR19081 reports that the polly dependence analysis causes some h264
compilation to hang. We adjust the compute out, to ensure we do not block on
expensive dependence calculations.

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@204168 91177308-0d34-0410-b5e6-96231b3b80d8
Fix source code formatting

git-svn-id: https://llvm.org/svn/llvm-project/polly/trunk@204169 91177308-0d34-0410-b5e6-96231b3b80d8