Import bmake-20230414

Relevant/interesting changes:

• make.1: document seemingly unexplained Error code 6.

o compat.c: CompatDeleteTarget skip .PHONY targets to be
consistent with JobDeleteTarget.
o job.c: fix memory leak in handling sysv :from=to modifiers
o unit tests for .MAKE.META.IGNORE_{FILTER,PATHS,PATTERNS}
o var.c: fix parsing of unevaluated subexpressions with
unbalanced '{}'
o cond.c: reduce complexity of evaluating expressions