make(1): move tests for the :tu and :_ modifiers into separate files

usr.bin/make/unit-tests/modmisc.exp

@@ -14,11 +14,8 @@ C:
 S:empty
 C:empty
 @:
-mod-tu-space: A   B
 mod-quote: new
 
 line
 mod-break-many-words: 500
-mod-remember: 1 2 3 1 2 3 1 2 3
-mod-remember: 1 2 3, SAVED=3
 exit status 0

usr.bin/make/unit-tests/modmisc.mk

@@ -1,4 +1,4 @@
-# $Id: modmisc.mk,v 1.45 2020/08/23 15:13:21 rillig Exp $
+# $Id: modmisc.mk,v 1.46 2020/08/23 15:18:43 rillig Exp $
 #
 # miscellaneous modifier tests
 
@@ -16,10 +16,8 @@ MOD_OPT=@d@$${exists($$d):?$$d:$${d:S,/usr,/opt,}}@
 MOD_SEP=S,:, ,g
 
 all:	modvar modvarloop modsysv emptyvar undefvar
-all:	mod-tu-space
 all:	mod-quote
 all:	mod-break-many-words
-all:	mod-remember
 
 # See also sysv.mk.
 modsysv:
@@ -58,11 +56,6 @@ undefvar:
 	@echo C:${:U:C,^$,empty,}
 	@echo @:${:U:@var@empty@}
 
-mod-tu-space:
-	# The :tu and :tl modifiers operate on the variable value
-	# as a single string, not as a list of words. Therefore,
-	# the adjacent spaces are preserved.
-	@echo $@: ${a   b:L:tu:Q}
 
 mod-quote:
 	@echo $@: new${.newline:Q}${.newline:Q}line
@@ -71,14 +64,6 @@ mod-quote:
 mod-break-many-words:
 	@echo $@: ${UNDEF:U:range=500:[#]}
 
-# Demonstrate the :_ modifier.
-# In the parameterized form, having the variable name on the right side
-# of the = assignment operator is confusing. Luckily this modifier is
-# only rarely needed.
-mod-remember:
-	@echo $@: ${1 2 3:L:_:@var@${_}@}
-	@echo $@: ${1 2 3:L:@var@${var:_=SAVED:}@}, SAVED=${SAVED}
-
 # To apply a modifier indirectly via another variable, the whole
 # modifier must be put into a single variable.
 .if ${value:L:${:US}${:U,value,replacement,}} != "S,value,replacement,}"

usr.bin/make/unit-tests/varmod-remember.exp

@@ -1 +1,3 @@
+1 2 3 1 2 3 1 2 3
+1 2 3, SAVED=3
 exit status 0

usr.bin/make/unit-tests/varmod-remember.mk

@@ -1,9 +1,12 @@
-# $NetBSD: varmod-remember.mk,v 1.2 2020/08/16 14:25:16 rillig Exp $
+# $NetBSD: varmod-remember.mk,v 1.3 2020/08/23 15:18:43 rillig Exp $
 #
 # Tests for the :_ modifier, which saves the current variable value
 # in the _ variable or another, to be used later again.
 
-# TODO: Implementation
-
+# In the parameterized form, having the variable name on the right side of
+# the = assignment operator is confusing.  In almost all other situations
+# the variable name is on the left-hand side of the = operator.  Luckily
+# this modifier is only rarely needed.
 all:
-	@:;
+	@echo ${1 2 3:L:_:@var@${_}@}
+	@echo ${1 2 3:L:@var@${var:_=SAVED:}@}, SAVED=${SAVED}

usr.bin/make/unit-tests/varmod-to-upper.exp

@@ -1 +1,2 @@
+mod-tu-space: A   B
 exit status 0

usr.bin/make/unit-tests/varmod-to-upper.mk

@@ -1,9 +1,9 @@
-# $NetBSD: varmod-to-upper.mk,v 1.2 2020/08/16 14:25:16 rillig Exp $
+# $NetBSD: varmod-to-upper.mk,v 1.3 2020/08/23 15:18:43 rillig Exp $
 #
 # Tests for the :tu variable modifier, which returns the words in the
 # variable value, converted to uppercase.
 
-# TODO: Implementation
-
-all:
-	@:;
+# The :tu and :tl modifiers operate on the variable value as a single string,
+# not as a list of words. Therefore, the adjacent spaces are preserved.
+mod-tu-space:
+	@echo $@: ${a   b:L:tu:Q}