Implement building ComponentTarget directly

I have no idea, why this was omitted; probably just an oversight.
While a path as the target specifier looks strange to me, e.g.
ids like ComponentTarget_svx/util/svx, they work as expected.

Change-Id: I6dd4d382dddb8ad67cdd397db3b1c985c14cd948
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/127023
Tested-by: Jenkins
Reviewed-by: Jan-Marek Glogowski <glogow@fbihome.de>

Makefile.in

@@ -130,6 +130,7 @@ gbuild_TARGETS := AllLangHelp \
 	CliNativeLibrary \
 	CliUnoApi \
 	CompilerTest \
+    ComponentTarget \
 	Configuration \
 	CppunitTest \
 	CustomTarget \

solenv/gbuild/ComponentTarget.mk

@@ -61,6 +61,8 @@ $(call gb_ComponentTarget_get_target,$(1)) : COMPONENTSOURCE := $(call gb_Compon
 
 $(call gb_ComponentTarget_get_target,$(1)) : $(call gb_ComponentTarget_get_source,$(patsubst CppunitTest/%,%,$(1)))
 
+$(call gb_Helper_make_userfriendly_targets,$(1),ComponentTarget,$(call gb_ComponentTarget_get_target,$(1)))
+
 ifneq ($(4),)
 $$(eval $$(call gb_Rdb_add_component,$(4),$(1)))
 endif

solenv/gbuild/gbuild.help.txt

@@ -68,6 +68,7 @@ AVAILABLE TARGETS
            o CliLibrary
            o CliNativeLibrary
            o CliUnoApi
+           o ComponentTarget
            o Configuration
            o CppunitTest
            o CustomTarget