define WIN32_LEAN_AND_MEAN on mingw #222

Job	Run time
build (ubuntu-latest, clean, i386-pc-msdosdjgpp, binutils gcc djgpp-2.05 watt32)	16m 19s
build (ubuntu-latest, clean, i386-pc-msdosdjgpp, binutils gcc djgpp-cvs watt32)	16m 35s
build (ubuntu-latest, clean, i386-pc-msdosdjgpp, gdb)	4m 33s
build (ubuntu-latest, clean, arm-eabi, binutils gcc newlib)	20m 36s
build (ubuntu-latest, clean, arm-eabi, gdb)	6m 36s
build (ubuntu-latest, clean, avr, binutils gcc avr-libc)	35m 22s
build (ubuntu-latest, clean, avr, gdb avarice simulavr avrdude)	54s
build (ubuntu-latest, clean, ia16-elf, binutils gcc newlib)	5m 32s
build (macos-latest, clean, i386-pc-msdosdjgpp, binutils gcc djgpp-2.05 watt32)	26m 30s
build (macos-latest, clean, i386-pc-msdosdjgpp, binutils gcc djgpp-cvs watt32)	25m 12s
build (macos-latest, clean, i386-pc-msdosdjgpp, gdb)	4m 8s
build (macos-latest, clean, arm-eabi, binutils gcc newlib)	37m 20s
build (macos-latest, clean, arm-eabi, gdb)	8m 1s
build (macos-latest, clean, avr, binutils gcc avr-libc)	1h 46m 49s
build (macos-latest, clean, avr, gdb avarice simulavr avrdude)	2m 57s
build (macos-latest, clean, ia16-elf, binutils gcc newlib)	15m 43s
	5h 33m 7s

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