MovableMan - fix usage of unordered_set::erase

[Architector4]

unordered_set::erase invalidates the pointer that was erased.

https://en.cppreference.com/w/cpp/container/unordered_set/erase.html

References and iterators to the erased elements are invalidated. Other iterators and references are not invalidated.

I also tested with a fresh C++ code file with -fsanitize-address and, indeed, the pattern of code of using an iterator variable to erase and then accessing through it reliably explodes.

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What prompted this is that I have just had a completely random segfault crash originating from SDL_Scancode () (????????) while playing the game. Here's the gdb backtrace (yes i play this game in debug build in gdb at this point lmao):

(gdb) bt
#0 0x0000555556b39558 in typeinfo name for SDL_Scancode ()
#1 0x0000555555ae47aa in RTE::MovableMan::Update (this=0x555557453f50) at ../Source/Managers/MovableMan.cpp:1618
#2 0x000055555567597c in RunGameLoop () at ../SourceMain.cpp:354
#3 0x000055555567658a in main (argc=1 argv=0x7fffffffdc88) at ../Source/Main.cpp:468

The last sensible location in that backtrace is right after the erase.

Nothing seems to be broken with this applied.

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There are comments and code around these spots that this commit touches that are apparently to work around the same issue I experienced. They're probably redundant/unneeded any more lol

[Causeless]

Feels dumb I didn't catch this. Nice one!

[numanair]

I just had a crash:

EXCEPTION_ACCESS_VIOLATION at address 0x7FF68FC2DC44.

Unable to get symbol name at address.
Symbol Handler failed to initialize because

The parameter is incorrect.

Stack trace (most recent call last):
#4    Object "", at 00007FF8979AE8D7, in BaseThreadInitThunk
#3    Source "D:\a\_work\1\s\src\vctools\crt\vcstartup\src\startup\exe_common.inl", line 288, in __scrt_common_main_seh
#2    Source "D:\a\Cortex-Command-Community-Project\Cortex-Command-Community-Project\Source\Main.cpp", line 471, in main
#1    Source "D:\a\Cortex-Command-Community-Project\Cortex-Command-Community-Project\Source\Main.cpp", line 355, in RunGameLoop
#0    Source "D:\a\Cortex-Command-Community-Project\Cortex-Command-Community-Project\Source\Managers\MovableMan.cpp", line 1617, in RTE::MovableMan::Update

Is it related to this change?

[Architector4]

Is it related to this change?

MovableMan.cpp", line 1617

Unlikely I think. Line 1617 is (*iIt)->DestroyScriptState(); and the one immediately after is delete (*iIt);, and both shouldn't cause crashing unless state was corrupted beforehand.

The game does keep having random rare memory corruption crashes in most random of places for me, and when I ran the game with gcc's undefined behavior analyzer, it kept spewing quite a bunch of various runtime errors related to things being wrong classes or something... I think the codebase is just kind of a swiss cheese at the moment with undefined behavior, and that inevitably bites.