runtime(java): Strive to remain compatible for at least Vim 7.0 #16727

Job	Run time
linux (tiny, clang, native)	2m 47s
macos (tiny, macos-12)	1m 17s
linux (tiny, gcc, native)	2m 29s
windows (HUGE, msvc, no, no, x64, stable)	6m 43s
macos (tiny, macos-14)	39s
windows (HUGE, mingw, yes, yes, x86, stable, yes)	11m 1s
macos (normal, macos-12)	6m 18s
linux (normal, clang, native)	5m 56s
windows (HUGE, msvc, no, yes, x86)	8m 34s
macos (normal, macos-14)	4m 37s
linux (normal, gcc, native)	6m 25s
windows (HUGE, mingw, yes, no, x64, yes)	9m 52s
macos (huge, macos-12)	13m 40s
linux (huge, clang, native)	9m 36s
windows (NORMAL, msvc, yes, no, x86)	6m 28s
macos (huge, macos-14)	13m 17s
linux (huge, gcc, native)	10m 41s
windows (NORMAL, mingw, no, yes, x64)	8m 48s
linux (tiny, clang, nogui)	2m 18s
windows (TINY, msvc, yes, yes, x64)	1m 49s
linux (tiny, gcc, nogui)	2m 7s
windows (TINY, mingw, no, no, x86)	2m 45s
linux (normal, gcc, i386, ./src/shadow)	10m 25s
linux (huge, gcc, uchar, testgui, true, dynamic)	9m 39s
linux (huge, clang, asan, 5.1)	16m 34s
linux (huge, gcc, unittests, true)	3m 24s
linux (normal, gcc, vimtags)	2m 45s
	3h 0m 54s

Provide feedback