Fix a few issues while skipping function bodies

 - In functions with try { } catch { }, only the try block would be
   skipped, not the catch blocks

 - The template functions would still be parsed.

 - The initializers within a constructor would still be parsed.

 - The inline functions within class would still be stored, only to be
   discared later.

 - Invalid code with try would assert (as in "int foo() try assert_here")

This attempt to do even less while skipping function bodies.

Differential Revision: http://reviews.llvm.org/D20821

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@272963 91177308-0d34-0410-b5e6-96231b3b80d8