The only functional change would be that we might emit multiple filename
segments on code like this:
void f() {
#include "p1/../t.h"
#include "p2/../t.h"
}
I believe these get separate DIFile metadata nodes, but will have the
same canonicalized absolute path. Previously by computing the path up
front and comparing it we would merge the line info segments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@257966 91177308-0d34-0410-b5e6-96231b3b80d8