Use PresumedLoc when emitting the 'included from' diagnostics.  For a malformed test like this:
Use PresumedLoc when emitting the 'included from' diagnostics.  For a malformed
test like this:

#line 4 "foo"

#define XX ?

#if XX
#endif

We now emit:

In file included from t.c:7:
foo:7:5: error: invalid token at start of a preprocessor expression
#if XX
    ^
foo:5:12: note: instantiated from:
#define XX ?
           ^

instead of:

In file included from t.c:7:
foo:7:5: error: invalid token at start of a preprocessor expression
#if XX
    ^
./t.h:6:12: note: instantiated from:
#define XX ?
           ^

(where the note doesn't obey #line or print the include stack when needed).

This fixes PR5617



git-svn-id: ffe668792ed300d6c2daa1f6eba2e0aa28d7ec6c@90554 91177308-0d34-0410-b5e6-96231b3b80d8

apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang,llvm-mirror/clang,apple/swift-clang,apple/swift-clang,apple/swift-clang,llvm-mirror/clang,llvm-mirror/clang