Fix false positives in shellcheck tests

Shellcheck became very smart, and it can detect that if there are only
action optional args that exit upon call, there is no need for a 'for'
to loop through args and, specifically, for 'shift' after 'case'.

Author: matejak

tests/regressiontests/test-env-base.m4

@@ -1,5 +1,10 @@
 #!/bin/bash
 
+# SC2317: Command appears to be unreachable
+# When there are only action optional arguments and no positional ones, the shift statement can be omitted.
+# The check smells risky, and its value is very low.
+# shellcheck disable=SC2317
+#
 # ARG_USE_ENV([ENVI_FOO], [def,ault], [A sample env, variable])
 # ARG_USE_ENV([ENVI_BAR], [], [A sample env, variable])
 # ARG_HELP()

tests/regressiontests/test-env-simple.m4

@@ -1,5 +1,10 @@
 #!/bin/bash
 
+# SC2317: Command appears to be unreachable
+# When there are only action optional arguments and no positional ones, the shift statement can be omitted.
+# The check smells risky, and its value is very low.
+# shellcheck disable=SC2317
+#
 # ARG_USE_ENV([ENVI_FOO], [def,ault])
 # ARG_HELP()
 # ARGBASH_GO

tests/regressiontests/test-prog.m4

@@ -1,5 +1,10 @@
 #!/bin/bash -e
 
+# SC2317: Command appears to be unreachable
+# When there are only action optional arguments and no positional ones, the shift statement can be omitted.
+# The check smells risky, and its value is very low.
+# shellcheck disable=SC2317
+#
 # ARG_VERSION([echo "$0 FOO"])
 # ARG_USE_PROGRAM([fulala], [FULALA], [fulala doesnt exist], [Testing program m4_fatal(BOOM!)])
 # ARG_HELP([Testing program m4_fatal(BOOM!)], [m4_fatal([CRASH!])])

tests/regressiontests/test-progs.m4

@@ -1,5 +1,10 @@
 #!/bin/bash -e
 
+# SC2317: Command appears to be unreachable
+# When there are only action optional arguments and no positional ones, the shift statement can be omitted.
+# The check smells risky, and its value is very low.
+# shellcheck disable=SC2317
+#
 # ARG_VERSION([echo "$0 FOO"])
 # ARG_USE_PROGRAM([fulala], [FULALA], [fulala doesnt exist], [Testing program m4_fatal(BOOM!)])
 # ARG_USE_PROGRAM([make], [MAKE], [GNU make missing], [GNU make - utility used for automation])