This saves us from having to bootstrap rcc in regular (non-cross)
compilations, as it can now link to QtCore. Actually un-bootstrapping
rcc is left as an exercise for the reader.
This commit discovered that MSVC cannot handle constexpr arrays bigger
than 256 kB, at which point it simply starts claiming that the constant
expressions using it are not constexpr. ICC has a similar problem at
64 kB, but it tells you why ("note: type "const unsigned char [65537]"
too large for constant-expression evaluation").
Note also that this requires gzip or zstd to be in PATH for compression
to happen. RCC linked to zlib, which is always present due to the
bundled copy. gzip's presence is not likely to be a problem on Unix
systems, but could be for Windows users, especially MSVC ones. If gzip
is not present, QtCore's size will increase by about 1910 kB of
read-only (sharable) data.
Change-Id: I2b1955a995ad40f3b89afffd15a3e65a94670242
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
0d4dea728f