Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Remove unnecessary includes.

Reviewed by: rodrigc

Avoid infinite loops when remaking makefiles not only
for Makefile targets but also for targets they depend on.

+ Add the -Q be-quiet flag for parallel jobs.
- Enable -Q by default for the moment - there is something weird
going on in the rescue build.

Exit with error code 2 when run with -k (continue if errors) and build failed.

If the special target .MAKEFILEDEPS exists, then enable the
"remaking makefiles" feature. Otherwise, follow traditional Pmake behavior.
(hash table will be regenerated and committed follow this commit)

Implement "Remaking Makefiles" feature:

After reading Makefile and all the files that are included using .include
or .sinclude directives (source Makefiles) make considers each source
Makefile as a target and tries to rebuild it. Both explicit and implicit
rules are checked and all source Makefiles are updated if necessary. If
any of the source Makefiles were rebuilt, make restarts from clean state.

To prevent infinite loops the following source Makefile targets are
ignored:
- :: targets that have no prerequisites but have commands
- ! targets
- targets that have .PHONY or .EXEC attributes
- targets without prerequisites and without commands

When remaking a source Makefile options -t (touch target), -q (query
mode), and -n (no exec) do not take effect, unless source Makefile is
specified explicitly as a target in make command line.
Additionally, system makefiles and .depend are not considered as a
Makefiles that can be rebuilt.

Reviewed by: harti

Move the Boolean and ReturnStatus stuff from sprite.h to util.h and
get rid of sprite.h.

Obtained from: DragonFlyBSD

Fix the fix for bin/72510 applied in job.c:1.70. Actually there have
been two maxJobs variables: one static in job.c and one global used in
main.c and parse.c. Makeing one global out of these was the wrong way
to fix the problem. Instead rename the global one to jobLimit and keep
maxJobs static in job.c.

Suggested by: rwatson
PR: bin/72510

Move some global variables to the correct files.

Submitted by: Max Okumoto <okumoto@ucsd.edu> (7.232)

Move declarations of variables belonging to the variable module
from globals.h into var.h.

Submitted by: Max Okumoto <okumoto@ucsd.edu> (7.209)

Move the declaration of VAR_CMD and VAR_GLOBAL from globals.h to var.h

Patch: 7.196
Submitted by: Max Okumoto <okumoto@ucsd.edu>

Implement a pseudo-target .WARN that allows toggeling the warning flags
for the current make. This does not override flags specified on the
command line and these settings are not passed to sub-makes.

Introduce a flag to enable extended warnings (-x) and make them off
by default. This should fix the problem of getting lots of errors
when building with an up-to-date make and old *.mk files.

Make the structure for handling the input stack local to the parse
module. The only module accessing it (the current line number) was the
condition module, so pass the current line number as a function argument.
Centralize the pushing of new input sources into one function
ParsePushInput() and rename the function handling the popping from ParseEOF()
to ParsePopInput(). Make the entire thing a little bit clearer, by holding
the current input source in the top element of the stack instead of
using extra variables for this. Use a type-safe intrusive list for the
input stack.

Make paths an explicite datatype instead of using the generic Lst.
A Path is now a TAILQ of PathElements each of which just points to
a reference counted directory. Rename all functions dealing with Paths
from the Dir_ prefix to a Path_ prefix.

Clean up include files and file including. Split nonints.h into pieces
that get included just where they are needed. All headers include the
headers that they need to compile (just with an empty .c file). Sort
includes alphabetically where apropriate and fix some duplicate commenting
for struct Job, struct GNode and struct Shell by removing one version and
inlining the comments into the structure declaration (the comments have been
somewhat outdated).

This patch does not contain functional changes (checked with md5).

Submitted by: Max Okumoto <okumoto@ucsd.edu>