Move PrettyStackTraceParserEntry to ParseAST.cpp

r128056 moved PrettyStackTraceParserEntry construction from Parser.h
to ParseAST.cpp, so there's no need to keep this class in a header.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@168731 91177308-0d34-0410-b5e6-96231b3b80d8