add the difference in the line marker phys line number and the

query point to the returned presumed location.  We now produce:

foo.h:92:2: warning: #warning blarg!
#warning blarg!
 ^
foo.h:93:2: warning: #warning blarg!
#warning blarg!
 ^
foo.h:94:2: warning: #warning blarg!
#warning blarg!
 ^

for:

#line 92 "foo.h"
#warning blarg!
#warning blarg!
#warning blarg!

blarg indeed!

llvm-svn: 63710