Add commands
type format info
type summary info
type synthetic info

These commands all take an expression, evaluate it, and show which of the respective formatter (if any) applies to the result of the expression

Fixes rdar://12059317


git-svn-id: https://llvm.org/svn/llvm-project/lldb/trunk@223511 91177308-0d34-0410-b5e6-96231b3b80d8