+/* Adjust a relative path name based on the reference path.
+ For example:
+
+ Relative path Reference path Result
+ ------------- -------------- ------
+ bar.o lib.a bar.o
+ foo/bar.o lib.a foo/bar.o
+ bar.o foo/lib.a ../bar.o
+ foo/bar.o baz/lib.a ../foo/bar.o
+ bar.o ../lib.a <parent of current dir>/bar.o
+ ../bar.o ../lib.a bar.o
+ ../bar.o lib.a ../bar.o
+ foo/bar.o ../lib.a <parent of current dir>/foo/bar.o
+ bar.o ../../lib.a <grandparent>/<parent>/bar.o
+ bar.o foo/baz/lib.a ../../bar.o
+
+ Note - the returned string is in a static buffer. */