[analyzer; new edges] Don't eliminate subexpr edge cycles if the line is long.

[analyzer; new edges] Don't eliminate subexpr edge cycles if the line is long.

Specifically, if the line is over 80 characters, or if the top-level
statement spans mulitple lines, we should preserve sub-expression edges
even if they form a simple cycle as described in the last commit, because
it's harder to infer what's going on than it is for shorter lines.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@183163 91177308-0d34-0410-b5e6-96231b3b80d8