Some tests failed because the bootstrap would continue to run even
detecting a problem. This puts in the missing early return statements
in the boost-build builtin rule to get the short circuit on error
like the original Jambase.
This ports the minimal Jambase to native C++. This removes the need for
mkjambase and the Jambase files. To accomplish that it adds C++
utility wrapers around Jam language primitives. Which makes future
similar work much easier.
Some system headers on POSIX systems indirectly include strings.h in extern "C"
region. This sometimes results in Boost.Build's strings.h being included into
such region, which marks all string_* functions as extern "C" and changes their
name mangling rules accordingly, which causes linking errors. To resolve this
header conflict, this commit renames strings.h to jam_strings.h. And strings.cpp
to jam_strings.cpp for consistency.
Fixes https://github.com/boostorg/build/issues/468.
When running in Linux containers the POSIX sysconf can return "too many"
cores or cpus. Instead we prefer using Linux specific sched_getaffinity
there.
This adds a `b2::system_info` class to obtain available information on
system we are running in. Currently provides CPU counts.
And currently only implemented for macOS.
