[CFG] Cache boolean evaluations of expressions to avoid multiple re-evaluations
during construction of branches for chained logical operators.

This makes -fsyntax-only for test/Sema/many-logical-ops.c about 32x times faster.

With measuring SemaExpr.cpp I see differences below the noise level.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@153297 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed