Revert "firebird: pass link options as LDFLAGS"

This reverts commit 3136c467.

Strangely firebird's build system apparently uses LDFLAGS on Linux
and Windows but not on MacOSX, whereas CXXFLAGS are consistently
put also on linker command lines.

Change-Id: I87dbe69a8d85b058ece9170105bf928cbd22db85

firebird/ExternalProject_firebird.mk

@@ -24,21 +24,22 @@ $(eval $(call gb_ExternalProject_register_targets,firebird,\
 # note: this can intentionally only build against internal atomic_op
 # note: this can intentionally only build against internal tommath
 
+# do not set LDFLAGS - it is mysteriously not used by firebird on MacOSX
 $(call gb_ExternalProject_get_state_target,firebird,build):
 	$(call gb_ExternalProject_run,build,\
 		unset MAKEFLAGS \
 		&& export PKG_CONFIG="" \
 		&& export CXXFLAGS=" \
-			$(if $(filter NO,$(SYSTEM_BOOST)),-I$(call gb_UnpackedTarball_get_dir,boost),$(BOOST_CPPFLAGS)) \
+			$(if $(filter NO,$(SYSTEM_BOOST)), \
+				-I$(call gb_UnpackedTarball_get_dir,boost),$(BOOST_CPPFLAGS) \
+				-L$(call gb_UnpackedTarball_get_dir,boost)/source/lib) \
 			$(if $(filter NO,$(SYSTEM_ICU)), \
 				-I$(call gb_UnpackedTarball_get_dir,icu)/source \
 				-I$(call gb_UnpackedTarball_get_dir,icu)/source/i18n \
 				-I$(call gb_UnpackedTarball_get_dir,icu)/source/common \
-				,$(ICU_CPPFLAGS))" \
-		&& export LDFLAGS=" \
-				-L$(OUTDIR)/lib \
-				$(if $(filter NO,$(SYSTEM_BOOST)), \
-					-L$(call gb_UnpackedTarball_get_dir,boost)/source/lib)" \
+				,$(ICU_CPPFLAGS)) \
+			-L$(OUTDIR)/lib \
+			" \
 		&& export LD_LIBRARY_PATH="$(OUTDIR)/lib:$(call gb_UnpackedTarball_get_dir,boost)/source/lib" \
 		&& export DYLD_LIBRARY_PATH="$(OUTDIR)/lib:$(call gb_UnpackedTarball_get_dir,boost)/source/lib" \
 		$(if $(filter WNT-MSC,$(OS)-$(COM)), && export PATH="$(PATH):$(shell cygpath $(OUTDIR)/lib):$(shell cygpath $(call gb_UnpackedTarball_get_dir,icu)/source/lib)") \