Enable OMRPORT_OMRSIG_SUPPORT globally in OpenJ9

Currently, OMRPORT_OMRSIG_SUPPORT is only defined while building the
port library. But, OMRPORT_OMRSIG_SUPPORT should be defined globally.
This will allow omrsig macros such as OMRSIG_SIGNAL and OMRSIG_SIGACTION
to be used consistently across OpenJ9. Thus, OMRPORT_OMRSIG_SUPPORT is
enabled globally.

Signed-off-by: Babneet Singh <sbabneet@ca.ibm.com>

runtime/gc_glue_java/configure_includes/configure_common.mk.ftl

@@ -26,6 +26,9 @@ TEMP_TARGET_DATASIZE := $(if $(findstring -64,$(SPEC)),64,32)
 CONFIGURE_ARGS += \
 <#if uma.spec.flags.opt_cuda.enabled>
   --enable-OMR_OPT_CUDA \
+</#if>
+<#if uma.spec.flags.port_omrsigSupport.enabled>
+  --enable-OMRPORT_OMRSIG_SUPPORT \
 </#if>
   --enable-OMR_GC \
   --enable-OMR_PORT \