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

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

MFC: r236338, r236339, r236346, r236347, r236365, & r236977
* Deprecate the FreeBSD make's ":U" (to-upper case) and ":L" (to-lower case)
modifiers for ":tu" and ":tl".
* make it easier to test newly-built make.
* Add "-V '${VAR}'" variable expansion from Portable Berkeley Make.
* regression test for '-V' command line option and the :t[lu] modifiers.

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

Approved by: re (implicit)

o The typo was intended as it stated in the comment. Revert last.

Spotted by: dfr

o Fix typo: .uudef -> .undef.

PR: misc/147462
Submitted by: Erik Cederstrand

Add ability to search up the directory hierarchy for the system directory.
Do by specifying ".../" with '-m' or MAKESYSPATH (new) environment variable.

Reviewed by: <sjg@NetBSD.org>
Obtained from: NetBSD (+ embellishment by me, sent back to NetBSD)

Regression test for r201456.

Delete the svn:mime-type property from these text files.

Set magic fbsd:nokeywords property that allows files to bypass
keyword expansion. (file-specific replacement for CVSROOT/exclude)

Add first tests for semicolon handling. The first test fails. This is
probably a bug in the parser.

Add more tests for escaped newline handling and fix a test that currently
should fail because of a bug in the parser (test 2).

Add a test for escaped newline handling.

Add support for TODO tests. These are tests that are supposed to fail,
because of a make bug that should be fixed.

Change the test infrastructure so that tests are easier to maintain and
so that make(1) will run in an almost clean environment and enhance the
description of the test infrastructure.

Add the ability to have multiple tests carried out per test script.

Give some tests more meaningful names.

Fix the usage message from the test scripts.

Make it possible to pass several commands to the test scripts like:
'sh test.t setup run compare clean'.

Add a test to check whether in compat mode make detectes builtins
on the command line and really executes the shell instead of directly
executing the command.

Add a test to ensure that in compat mode when a line contains no
shell meta characters it is not passed to the shell, but the command
is executed directly (given that the line is not a shell builtin) and
that the line with a meta character is passed to the shell.

Add a test that test whether we can replace the shell to use by
make with another shell and set all its parameters (meta and builtins
not tested here).

Some test cases for .SHELL target: builtin shell selection and
changing the path of a builtin shell.

Add an initial regression test suite for make(1).

Submitted by: Max Okumoto <okumotu@ucsd.edu> (partly, initial version)