Import bmake-20200902vendor/NetBSD/bmake/20200902

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.

1 files changed, 13 insertions, 0 deletions

diff --git a/unit-tests/varmod-order-reverse.mk b/unit-tests/varmod-order-reverse.mk
new file mode 100644
index 000000000000..fa9d179560c8
--- /dev/null
+++ b/unit-tests/varmod-order-reverse.mk
@@ -0,0 +1,13 @@
+# $NetBSD: varmod-order-reverse.mk,v 1.3 2020/08/16 20:13:10 rillig Exp $
+#
+# Tests for the :Or variable modifier, which returns the words, sorted in
+# descending order.
+
+NUMBERS=	one two three four five six seven eight nine ten
+
+.if ${NUMBERS:Or} != "two three ten six seven one nine four five eight"
+.error ${NUMBERS:Or}
+.endif
+
+all:
+	@:;