Checks for equivalence by comparing the filename contents (not the pointer) and character location.
opEquals() / toHash() for AA key usage
Configure how display is done
use for default initialization of const ref Loc's
utf8 code unit index relative to start of line, starting from 1
utf8 code unit index relative to start of file, starting from 0
zero-terminated filename string, either absolute or relative to cwd
line number, starting from 1
A source code location
Used for error messages, __FILE__ and __LINE__ tokens, __traits(getLocation, XXX), debug info etc.