Cautious (probably unnecessary) protection against overflows #2984

Job	Run time
Windows x64 MinGW GCC	27m 25s
Rocky Linux 8 x64 Clang gnustep-2.2	2m 22s
Windows x64 MinGW Clang gnustep-2.2	26m 1s
Windows x64 MSVC Clang gnustep-2.2	20m 44s
Ubuntu x64 GCC	5m 14s
Windows arm64 MSVC Clang gnustep-2.2	38m 49s
Rocky Linux 9 x64 Clang gnustep-2.2	6m 2s
Ubuntu x64 Clang gnustep-2.2	5m 24s
	2h 12m 1s

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