Merge branch 'rj/build-tweaks'

Various build tweaks, including CSPRNG selection on some platforms. * rj/build-tweaks: config.mak.uname: set CSPRNG_METHOD to getrandom on Linux config.mak.uname: add arc4random to the cygwin build config.mak.uname: add sysinfo() configuration for cygwin builtin/gc.c: correct RAM calculation when using sysinfo config.mak.uname: add clock_gettime() to the cygwin build config.mak.uname: add HAVE_GETDELIM to the cygwin section config.mak.uname: only set NO_REGEX on cygwin for v1.7 config.mak.uname: add a note about NO_STRLCPY for Linux Makefile: remove NEEDS_LIBRT build variable meson.build: set default help format to html on windows meson.build: only set build variables for non-default values Makefile: only set some BASIC_CFLAGS when RUNTIME_PREFIX is set meson.build: remove -DCURL_DISABLE_TYPECHECK