Commons up the code for reading files and buffers, and allows a further
change where we don't copy the data out of the buffer when generating 'lines.
This will speed up makefile parsing (esp .if clauses).
(Almost all the debug output went there, but some went to stderr.)
Split the parsing of -d (debug flags) out into its own routine.
Allow the output filename to be changed by specifying -dF<file> to create
a log file, or -dF+<file> to append to it. <file> may be stdout or stderr.
Also change so that -d-<flags> acts on <flags> locally but doesn't copy
them to MAKEFLAGS so they aren't inherited by child makes.
I'm not 100% happy with the command line syntax for the above, so they are
currently undocumented.
Instead of adding MAKE_BOOTSTRAP for hosted environments, i.e., when
you want things simple, instead add MAKE_NATIVE to get those hugely
important features like __RCSID().
It's now possible to build make on some hosts with: cc *.c */*.c
1. Compensate for h-pox assert brain damage where it gets confused by the
string in: assert(!memcmp(foo, "in", 2)); I miss the h-pox broken compiler,
I had not had to work around it for years.
2. Oh, finally h-pox has random() and utimes(). We don't need our own anymore.
