Introduce non-deterministic ordering into goal and prerequisite
traversal to help tease out inconsistent failures that may happen
when running in parallel build mode.
Introduce second order into each dependency chain:
1. Existing order is syntactic order reachable via 'dep->next'
2. New order is shuffled order stored as 'dep->shuf' in each 'dep'
When updating goals and prerequisites and '--shuffle' is provided,
use the shuffled order to walk the graph. When automatic variable
are set always use the syntactic order of parameters.
* Makefile.am: Add new src/shuffle.c and src/shuffle.h file.
* build_w32.bat: Ditto.
* builddos.bat: Ditto.
* makefile.com: Ditto.
* po/POTFILES.in: Ditto.
* doc/make.texi: Add documentation for --shuffle.
* doc/make.1: Ditto.
* src/dep.h (DEP): Add the shuf pointer.
* src/filedef.h (struct file): Add was_shuffled flag.
* src/main.c: (shuffle_mode): Global flag for the shuffle mode.
(usage): Add the --shuffle option.
(switches): Ditto.
(main): Set shuffle_mode based on the command line parameter.
Reshuffle prerequisites if requested.
* src/remake.c (update_goal_chain): Walk the shuffled list if enabled.
(update_file_1): Ditto.
* src/shuffle.h: Provide an interface for shuffling prerequisites.
* src/shuffle.c: Implement option parsing and prerequisite shuffling.
* tests/scripts/options/shuffle: Test shuffle option and modes.
Add debug options to print recipes even if they would otherwise be
silent, and to print the reason that a target was considered out of
date.
Modify --trace to simply be a shorthand for --debug=print,why.
* NEWS: Announce changes.
* doc/make.texi (Summary of Options): Document the new options.
* doc/make.1: Ditto.
* src/debug.h: Add new flags DB_PRINT and DB_WHY.
* src/makeint.h: Remove the trace_flag variable.
* src/job.c (start_job_command): Check debug flags not trace_flag.
(new_job): Ditto.
* src/main.c (trace_flag): Make a static variable for switches.
(decode_debug_flags): Set DB_PRINT and DB_WHY if trace_flag is set.
* tests/scripts/variables/GNUMAKEFLAGS: Update known-good messages.
* tests/scripts/variables/MAKEFLAGS: Ditto.
Move the source code (other than glob) into the "src" subdirectory.
Update all scripting and recommendations to support this change.
* *.c, *.h, w32/*: Move to src/
* configure.ac, Makefile.am, maintMakefile: Locate new source files.
* Basic.mk.template, mk/*: Update for new source file locations.
* NEWS, README.DOS.template: Update for new locations.
* build.template, build_w32.bat, builddos.bat: Ditto.
* po/POTFILES.in: Ditto
* tests/run_make_tests.pl, tests/scripts/features/load*: Ditto.
* make.1: Move to doc.
* mk/VMS.mk: Add support for building on VMS (hopefully).
* makefile.vms, prepare_w32.bat: Remove.
* SCOPTIONS: Update to define HAVE_CONFIG_H
