_mmap.o should be added to libc.a, not crt0.o

libc/sysdeps/linux/v850/Makefile

@@ -18,13 +18,13 @@ CFLAGS+= -I../ -D__ASSEMBLER__ -DASM_GLOBAL_DIRECTIVE=.globl
 
 TARGET_MACHINE_TYPE=$(shell $(CC) -dumpmachine)
 
-CRT0=crt0.S _mmap.c
+CRT0=crt0.S
 CRT0_OBJ=$(patsubst %.S,%.o, $(CRT0))
 
 SSRC=setjmp.S longjmp.S vfork.S
 SOBJS=$(patsubst %.S,%.o, $(SSRC))
 
-CSRC=
+CSRC=_mmap.c
 COBJS=$(patsubst %.c,%.o, $(CSRC))
 
 OBJS=$(SOBJS) $(MOBJ) $(COBJS)