It is similar to --reconfigure but completely wipe the build directory
first. It is intended to make easier to rebuild project when builddir somehow
got corrupted.
Fixes#3542.
Write command line options into a separate file to be able to
reconfigure from scatch in the case coredata cannot be loaded. The most
common case is when we are reconfiguring with a newer meson version.
This means that we should try as much as possible to maintain backward
compatibility for the cmd_line.txt file format.
The main difference with a normal reconfigure is it will use new
default options values and will read again environment variables like
CFLAGS, etc.
This has the adventage that "meson --help" shows a list of all commands,
making them discoverable. This also reduce the manual parsing of
arguments to the strict minimum needed for backward compatibility.
Xavier Claessens