The emulator/simulator has two choices: it either works with the debug file output by the assembler, or it works directly with the sources.
not a choice, it works with BOTH

In the second case, the original source file DOES STILL CONTAIN the include statement. There is NOTHING which would prevent the simulator program from parsing it and discovering the file which has been included and displaying it properly.
well there is:
if the assembler/compiler/linker does not give the path to the include file, how is the emulator going to find it? The connections made by the compiler are not forwarded to the linker which, after all is which gives the emulator what it works with.

Thus the problem is NOT the emulator (Jan, please stop the confusion, do not mix 'simulator' and 'emulator') but the compiler/linker.

Now, why not 'fix' the compiler/linker, I tell you why: every darn emulator out there would blow up when the file format changed to include what you suggest.

anyone interested in making a billion dollars? easy: come up with a means of guaranteeing forward compatibility and patent it.

Erik