Revert the runtests:: change but in an extensible way

Use only %.t files in new TESTSCRIPTS.t var for Perl tests.
TAPFILES and JUNITFILES can be appended to by other rules.
The runtests and test-results rules have no direct recipes.
Added run-tap-tests and tap-results rules, simlified recipe.
Make %.tap:%.t and %.xml:%.tap into static pattern rules.

configure/RULES_BUILD

@@ -108,11 +108,12 @@ TESTPRODTARGETS += $(TESTPRODNAME) $(TESTMUNCHNAME)
 #   Test result files
 #
 
-# Enable testing if this host can run tests on the current target
-ifneq (,$(findstring $(T_A),$(EPICS_HOST_ARCH) $(CROSS_COMPILER_RUNTEST_ARCHS)))
+# Enable testing if this host can run tests for the current target
+ifneq (,$(filter $(T_A), $(EPICS_HOST_ARCH) $(CROSS_COMPILER_RUNTEST_ARCHS)))
 RUNTESTS_ENABLED = YES
-TAPFILES += $(TESTSCRIPTS:.t=.tap)
-JUNITFILES += $(TAPFILES:.tap=.xml)
+TESTSCRIPTS.t = $(filter %.t, $(TESTSCRIPTS))
+TAPFILES += $(TESTSCRIPTS.t:.t=.tap)
+JUNITFILES += $(TESTSCRIPTS.t:.t=.xml)
 endif
 
 #---------------------------------------------------------------
@@ -332,17 +333,22 @@ $(MODNAME): %$(MODEXT): %$(EXE)
 #---------------------------------------------------------------
 # Automated testing
 
-ifneq ($(strip $(TESTSCRIPTS)),)
-runtests:: $(TESTSCRIPTS)
+runtests: run-tap-tests
+run-tap-tests: $(TESTSCRIPTS.t)
+ifneq ($(TESTSCRIPTS.t),)
 ifdef RUNTESTS_ENABLED
-	-$(PERL) -MTest::Harness -e 'runtests @ARGV if @ARGV;' $^
+	$(PROVE) --failures --color $^ || $(PROVE_FAILURE)
 endif
 endif
 
-test-results: tapfiles
+tapfiles: $(TAPFILES)
+junitfiles: $(JUNITFILES)
+
+test-results: tap-results
+tap-results: $(TAPFILES)
 ifneq ($(strip $(TAPFILES)),)
 ifdef RUNTESTS_ENABLED
-	-$(PROVE.tap) --failures --color $(TAPFILES) || $(PROVE_FAILURE)
+	$(PROVE.tap) --failures --color $^ || $(PROVE_FAILURE)
 endif
 
 CURRENT_TAPFILES := $(wildcard $(TAPFILES))
@@ -357,16 +363,13 @@ ifneq ($(CURRENT_JUNITFILES),)
 	$(RM) $(CURRENT_JUNITFILES)
 endif
 
-tapfiles: $(TESTSCRIPTS) $(TAPFILES)
-junitfiles: $(JUNITFILES)
-
 # A .tap file is the output from running the associated test script
-%.tap: %.t
+$(TAPFILES): %.tap: %.t
 ifdef RUNTESTS_ENABLED
 	-$(PERL) $< -tap > $@
 endif
 
-%.xml: %.tap
+$(JUNITFILES): %.xml: %.tap
 	$(TAPTOJUNIT) --puretap --output $@ --input $< $*
 
 # If there's a perl test script (.plt) available, use it
@@ -513,8 +516,8 @@ $(INSTALL_TEMPLATES_SUBDIR)/%: %
 .PRECIOUS: $(COMMON_INC)
 
 .PHONY: all host inc build install clean rebuild buildInstall build_clean
-.PHONY: runtests tapfiles clean-tests test-results junitfiles
-.PHONY: checkRelease warnRelease noCheckRelease
+.PHONY: runtests run-tap-tests tapfiles junitfiles test-results tap-results
+.PHONY: clean-tests checkRelease warnRelease noCheckRelease
 
 endif # BASE_RULES_BUILD
 #	EOF RULES_BUILD