fix --enable-mergelibs dependencies

..and create gb_BUILD_HELPER_LIBS in instdir, so that they are found
when gb_BUILD_HELPER_TOOLS link against them.
Altough it's ugly - we don't want them in instdir otherwise.

Change-Id: Ia946eceeaf7eada0c3b42379e95af9bdbf52957f

solenv/gbuild/LinkTarget.mk

@@ -900,6 +900,7 @@ $(call gb_LinkTarget_get_headers_target,$(1)) : \
 
 endef
 
+# libraries which are merged but need to be built for gb_BUILD_HELPER_TOOLS
 gb_BUILD_HELPER_LIBS := basegfx \
 	cppu \
 	cppuhelper \
@@ -911,8 +912,8 @@ gb_BUILD_HELPER_LIBS := basegfx \
 	unoidl \
 	xmlreader \
 
+# tools libmerged depends on, so they link against gb_BUILD_HELPER_LIBS
 gb_BUILD_HELPER_TOOLS := cppumaker \
-	regmerge \
 	rsc \
 	svidl \
 	unoidl-check \
@@ -920,12 +921,12 @@ gb_BUILD_HELPER_TOOLS := cppumaker \
 
 # call gb_LinkTarget__is_build_lib,linktargetname
 define gb_LinkTarget__is_build_lib
-$(if $(filter $(1),$(foreach lib,$(gb_BUILD_HELPER_LIBS),$(call gb_Library__get_workdir_linktargetname,$(lib)))),$(true),$(false))
+$(if $(filter $(call gb_LinkTarget__get_workdir_linktargetname,$(1)),$(foreach lib,$(gb_BUILD_HELPER_LIBS),$(call gb_Library__get_workdir_linktargetname,$(lib)))),$(true),$(false))
 endef
 
 # call gb_LinkTarget__is_build_tool,linktargetname
 define gb_LinkTarget__is_build_tool
-$(if $(filter $(1),$(foreach exe,$(gb_BUILD_HELPER_TOOLS),$(call gb_Executable__get_workdir_linktargetname,$(exe)))),$(true),$(false))
+$(if $(filter $(call gb_LinkTarget__get_workdir_linktargetname,$(1)),$(foreach exe,$(gb_BUILD_HELPER_TOOLS),$(call gb_Executable__get_workdir_linktargetname,$(exe)))),$(true),$(false))
 endef
 
 # call gb_LinkTarget_use_libraries,linktarget,libs

solenv/gbuild/TargetLocations.mk

@@ -397,7 +397,7 @@ define gb_Library__get_workdir_linktargetname
 Library/$(call gb_Library_get_filename,$(1))
 endef
 define gb_Library__get_linktarget_target
-$(if $(filter-out $(gb_MERGEDLIBS),$(1)),$(call gb_Library_get_install_target,$(1)),$(WORKDIR)/LinkTarget/$(call gb_Library__get_workdir_linktargetname,$(1)))
+$(call gb_Library_get_install_target,$(1))
 endef
 # this returns a tuple of both the linktargetname, and the target file
 define gb_Library_get_linktarget