[analyzer] Bump down the max size of functions being analyzed.

With the new setting, we are not going to inline any functions that are
more than 50 basic blocks. (The analyzer is 20% faster on several
especially bad benchmarks with the new default.)

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@171891 91177308-0d34-0410-b5e6-96231b3b80d8