emscripten: simulate mouse autocapture. #85

Job	Run time
Create test plan	3s
level1 / Haiku	1m 54s
level2 / Android (Gradle)	2m 49s
level2 / Windows (msys2, mingw32)	9m 10s
level2 / Android (CMake)	3m 11s
level2 / Windows (MSVC, ARM64)	4m 5s
level2 / Ubuntu 20.04 (Intel oneAPI)	8m 18s
level2 / PowerPC64	1m 51s
level2 / Windows (MSVC, clang-cl x86)	5m 53s
level2 / PowerPC	1m 56s
level2 / NetBSD	2m 49s
level2 / LoongArch64	2m 53s
level2 / Sony PlayStation Vita (GLES w/ PVR_PSP2)	3m 19s
level2 / Sony PlayStation Portable	3m 47s
level2 / Nintendo 3DS	1m 57s
level2 / MacOS (Framework) (arm64)	2m 49s
level2 / Windows (msys2, mingw64)	8m 23s
level2 / Android (Android.mk)	1m 10s
level2 / Steam Linux Runtime (Sniper)	3m 3s
level2 / iOS (CMake & xcode)	2m 3s
level2 / Windows (msys2, clang32)	7m 31s
level2 / RISC OS	1m 19s
level2 / Ubuntu 22.04	4m 45s
level2 / Windows (MSVC, x86)	6m 4s
level2 / Windows (MSVC, x64)	5m 29s
level2 / Sony PlayStation Vita (GLES w/ pib)	3m 7s
level2 / Windows (msys2, ucrt64)	8m 33s
level2 / FreeBSD	2m 34s
level2 / tvOS (CMake & xcode)	2m 51s
level2 / Windows (MSVC, clang-cl x64)	5m 23s
level2 / Windows (msys2, clang64)	5m 50s
level2 / MacOS (GNU prefix)	3m 55s
level2 / Ubuntu 20.04	5m 0s
level2 / GDK (MSVC, x64)	1m 34s
level2 / Android (CMake, lean)	3m 14s
level2 / Windows (MSVC, ARM)	3m 44s
level2 / Ubuntu 20.04 (Intel Compiler)	5m 27s
level2 / MacOS (Framework) (x64)	12m 6s
level2 / Emscripten	9m 14s
level2 / Sony PlayStation 2	5m 6s
	2h 54m 9s

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