[SV 54740] Ensure .SILENT settings do not leak into sub-makes

Create a new variable run_silent to hold the current instance's global
silence setting, allowing silent_flag to represent only whether the -s
option was provided on the command line.

* src/makeint.h: Change silent_flag variable to run_silent.
* src/job.c: Ditto.
* src/remake.c: Ditto.
* src/file.c: Ditto.
* src/main.c: Add a new global variable run_silent.
(decode_switches): After switches are decoded, initialize run_silent.
* tests/scripts/targets/SILENT: Add a test for recursive behavior.

tests/scripts/targets/SILENT

@@ -1,31 +1,33 @@
 #                                                                    -*-perl-*-
 
-$description = "The following tests the special target .SILENT.  By simply\n"
-              ."mentioning this as a target, it tells make not to print\n"
-              ."commands before executing them.";
+$description = "Test the special target .SILENT.";
 
-$details = "This test is the same as the clean test except that it should\n"
-          ."not echo its command before deleting the specified file.\n";
+run_make_test(q!
+.PHONY: M a b
+M: a b
+.SILENT : b
+a b: ; echo $@
+!,
+              '', "echo a\na\nb");
 
-$example = "EXAMPLE_FILE";
+run_make_test(q!
+.PHONY: M a b
+M: a b
+.SILENT:
+a b: ; echo $@
+!,
+              '', "a\nb");
 
-open(MAKEFILE,"> $makefile");
-print MAKEFILE qq!
-.SILENT : clean
-clean: ; $CMD_rmfile $example
-!;
-close(MAKEFILE);
+# SV 54740 : don't inherit .SILENT settings in sub-makes
+run_make_test(q!
+.PHONY: M r a b
+r: a b ; @$(MAKE) -f #MAKEFILE# M V=x
+a b: ; echo $@
 
-touch($example);
-
-$answer = '';
-run_make_with_options($makefile,"clean",&get_logfile,0);
-if (-f $example) {
-  $test_passed = 0;
-}
-compare_output($answer,&get_logfile(1));
-
-# Just in case
-unlink($example);
+V =
+$V.SILENT:
+M: a b
+!,
+              '--no-print-directory', "a\nb\necho a\na\necho b\nb");
 
 1;