Quiet some deprecated warnings.

[MaddTheSane]

This will quiet some deprecated warnings in regards to Cocoa methods, including:

• NSDocument hates NSString-based path methods: initial work on migrating to NSURL-based methods.
• replace -[NSGraphicsContext graphicsPort] with -[NSGraphicsContext CGContext].

Note that I used tabs instead of spaces. I'll probably fix it in another commit.

[LIJI32]

Many of those are done intentionally:

• NS_NOESCAPE and other "Swift Propaganda" such as nullability macros are intentionally not used. Swift will not be used in this codebase so there's no point I've read about NS_NOESCAPE and it seems to introduce optimization benefits to blocks in Objective-C (and C) as well, so that one's good.
• self-> is not used by convention, -Wimplicit-retain-selfis intentionally not enabled in the Makefile
• I intentionally use the deprecated NSString APIs instead of the NSURL APIs because they're easier to work with; they've been deprecated since 10.4 and Apple shows no intention of removing them
• graphicsPort is not supported on Mavericks (10.9) which is still supported by SameBoy. I assume you're not using the Makefile for compiling? Properly selecting the right deployment target (10.9) should silence this warning.
• bool is preferred for BOOL by convention, specifically so you don't have to add != 0 like that.

The other changes are welcome, once the tabs are fixed.

[MaddTheSane]

Yeah, I used an Xcode project, mainly to see how it would compile under Apple Silicon.
One thing about BOOL under Apple Silicon: it'll by typedef'd to bool. Why Apple didn't do this in x86_64, or even i386, I don't know.

Ah, I thought -[NSGraphicsContext CGContext] was introduced in 10.9, but the header says it's only on 10.10.

My new commit removes the migration to NSURL, but still calls -fileSystemRepresentation.

[LIJI32]

The Makefile already compiles ARM-Intel fat binaries if you use CONF=fat_release

[MaddTheSane]

Ah, so Universal compilation is already handled.
Another reason why I wanted to build it under Xcode was to use Xcode assets, including handling of dark mode. But you have code that works around it, so using Xcode assets would just be another thing to worry about for the makefile. Better to just leave it as-is for now.

Also, compiling Swift source using a makefile is a pain! I should know, my NetHack3D code has parts that are Swift, that have to interact with the build system.