Apply perl rules for .tap and .xml only to perl tests

Don't apply the %.tap: %.t and %.xml: %.tap rules to tap and junit
result files from other test frameworks.
(They would overwrite the other frameworks' own rules.)

configure/RULES_BUILD

@@ -112,8 +112,10 @@ TESTPRODTARGETS += $(TESTPRODNAME) $(TESTMUNCHNAME)
 ifneq (,$(filter $(T_A), $(EPICS_HOST_ARCH) $(CROSS_COMPILER_RUNTEST_ARCHS)))
 RUNTESTS_ENABLED = YES
 TESTSCRIPTS.t = $(filter %.t, $(TESTSCRIPTS))
-TAPFILES += $(TESTSCRIPTS.t:.t=.tap)
-JUNITFILES += $(TESTSCRIPTS.t:.t=.xml)
+TAPFILES.t += $(TESTSCRIPTS.t:.t=.tap)
+JUNITFILES.t += $(TESTSCRIPTS.t:.t=.xml)
+TAPFILES += $(TAPFILES.t)
+JUNITFILES += $(JUNITFILES.t)
 endif
 
 #---------------------------------------------------------------
@@ -364,12 +366,12 @@ ifneq ($(CURRENT_JUNITFILES),)
 endif
 
 # A .tap file is the output from running the associated test script
-$(TAPFILES): %.tap: %.t
+$(TAPFILES.t): %.tap: %.t
 ifdef RUNTESTS_ENABLED
 	-$(PERL) $< -tap > $@
 endif
 
-$(JUNITFILES): %.xml: %.tap
+$(JUNITFILES.t): %.xml: %.tap
 	$(TAPTOJUNIT) --puretap --output $@ --input $< $*
 
 # If there's a perl test script (.plt) available, use it