Merge pull request #6307 from kit-ty-kate/no-default-ocaml-system #4118

Job	Run time
Analyse	8s
Cygwin	4s
Build-macOS (4.14.2)	3m 24s
Hygiene	22s
Build-Linux (4.08.1)	4m 38s
Build-macOS (5.3.0)	3m 19s
Build-Linux (4.09.1)	2m 20s
Test-macOS (4.14.2)	26m 54s
Build-Linux (4.10.2)	2m 21s
Test-macOS (5.3.0)	25m 53s
Build-Linux (4.11.2)	2m 20s
Build-Linux (4.12.1)	2m 35s
Build-Linux (4.13.1)	2m 24s
Build-Linux (5.0.0)	2m 35s
Build-Linux (5.1.1)	2m 28s
Build-Linux (5.2.1)	2m 17s
Build-Linux (4.14.2)	2m 25s
Build-Linux (5.3.0)	2m 21s
Build-Windows (x86_64-pc-cygwin, x86_64-pc-cygwin, 4.14.2)	36m 7s
Build-Windows (i686-w64-mingw32, x86_64-pc-cygwin, 4.14.2)	41m 18s
Build-Windows (x86_64-w64-mingw32, x86_64-pc-cygwin, 4.14.2)	38m 48s
Build-Windows (i686-pc-windows, x86_64-pc-cygwin, 4.14.2)	43m 29s
Build-Windows (x86_64-pc-windows, x86_64-pc-cygwin, 4.14.2)	44m 19s
Build-Windows (x86_64-w64-mingw32, x86_64-pc-cygwin, 5.3.0)	41m 34s
Build-Windows (x86_64-pc-windows, x86_64-pc-cygwin, 5.3.0)	43m 0s
Upgrade-macOS (4.14.2)	1m 55s
Solvers-macOS (z3, 4.14.2)	1m 31s
Solvers-macOS (z3, 5.3.0)	1m 23s
Upgrade-macOS (5.3.0)	1m 46s
Solvers-macOS (0install, 4.14.2)	1m 21s
Solvers-macOS (0install, 5.3.0)	1m 19s
Doc-Linux (4.14.2)	1m 9s
Test-Linux (4.14.2)	9m 23s
Solvers-Linux (z3, 4.14.2)	1m 1s
Cold-Linux	5m 18s
Doc-Linux (5.3.0)	1m 18s
Test-Linux (5.3.0)	9m 6s
Solvers-Linux (z3, 5.3.0)	1m 5s
Solvers-Linux (0install, 4.14.2)	1m 34s
Upgrade-Linux (4.14.2)	1m 32s
Solvers-Linux (0install, 5.3.0)	1m 32s
Upgrade-Linux (5.3.0)	1m 20s
	7h 0m 56s

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