+ enabled compilation of unit strings for the ZX Spectrum

rtl/zxspectrum/Makefile

@@ -923,7 +923,7 @@ ifdef NO_EXCEPTIONS_IN_SYSTEM
 override FPCOPT+=-dNO_EXCEPTIONS_IN_SYSTEM
 endif
 ifeq ($(CPU_OS_TARGET),z80-zxspectrum)
-override TARGET_UNITS+=$(SYSTEMUNIT) $(OBJPASUNIT) $(UUCHARUNIT) si_prc
+override TARGET_UNITS+=$(SYSTEMUNIT) $(OBJPASUNIT) $(UUCHARUNIT) $(STRINGSUNIT) si_prc
 endif
 override INSTALL_FPCPACKAGE=y y
 ifeq ($(CPU_OS_TARGET),z80-zxspectrum)

rtl/zxspectrum/Makefile.fpc

@@ -5,7 +5,7 @@
 main=rtl
 [target]
 loaders=
-units=$(SYSTEMUNIT) $(OBJPASUNIT) $(UUCHARUNIT) si_prc
+units=$(SYSTEMUNIT) $(OBJPASUNIT) $(UUCHARUNIT) $(STRINGSUNIT) si_prc
 
 [require]
 nortl=y