Quite a lot of churn on style, but lots of
good work refactoring complicated functions
and lots more unit-tests.
Thanks mostly to rillig at NetBSD
Some interesting entries from ChangeLog
o .MAKE.{UID,GID} represent uid and gid running make.
o allow env var MAKE_OBJDIR_CHECK_WRITABLE=no to skip writable
checks in InitObjdir. Explicit .OBJDIR target always allows
read-only directory.
o add more unit tests for META MODE
Change-Id: I4d3bcf08b4c864d98b343f602efe5a75dbfa7a94
Lots of code refactoring, simplification and cleanup.
Lots of new unit-tests providing much higher code coverage.
All courtesy of rillig at netbsd.
Other significant changes:
o new read-only variable .SHELL which provides the path of the shell
used to run scripts (as defined by the .SHELL target).
o new debug option -dl: LINT mode, does the equivalent of := for all
variable assignments so that file and line number are reported for
variable parse errors.
from ChangeLog:
o cond.c: do not eval unnecessary terms of conditionals.
o meta.c: report error if lseek in filemon_read fails
o str.c: performance improvement for Str_Match for multiple '*'
o dieQuietly: supress the failure output from make
when failing node is a sub-make or a sibling failed.
This cuts down greatly on unhelpful noise at the end of
build log. Disabled by -dj or .MAKE.DIE_QUIETLY=no
o unit test for :Or
