It sounds like the sort of compile-time code that you're talking about is closer to "buildtime" code in Zig, that is Zig code compiled for the host platform and executed by the build system to generate code (or data) to be used when compiling for the target system. As it stands now, there's absolutely nothing special about buildtime code in Zig other than Zig's build system providing good integration.
On the other hand, "comptime" is actually executed within the compiler similar to C++'s `consteval`. There's no actual "emulation" going on. The "emulation" is just ensuring that any observable characteristic of the platform matches the target, but it's all smoke and mirrors. You can create pointers to memory locations, but these memory locations and pointers are not real. They're all implemented using the same internal mechanisms that power the rest of the compilation process. The compiler's logic to calculate the value of a global constant (`const a: i32 = 1 + 2;`) is the "comptime" that allows generic functions, ORMs, and all these other neat use cases.
On the other hand, "comptime" is actually executed within the compiler similar to C++'s `consteval`. There's no actual "emulation" going on. The "emulation" is just ensuring that any observable characteristic of the platform matches the target, but it's all smoke and mirrors. You can create pointers to memory locations, but these memory locations and pointers are not real. They're all implemented using the same internal mechanisms that power the rest of the compilation process. The compiler's logic to calculate the value of a global constant (`const a: i32 = 1 + 2;`) is the "comptime" that allows generic functions, ORMs, and all these other neat use cases.