armv7a:add cfi instrcutions to debug

(gdb) bt
    #0  memset () at machine/arm/armv7-a/gnu/arch_memset.S:45
    #1  0x0407222e in memset (n=4, c=65, s=0x40269d94) at /home/mi/ssd/dev-system/nuttx/include/string.h:203
    #2  test_memset () at hello_main.c:57
    #3  hello_main (argc=<optimized out>, argv=<optimized out>) at hello_main.c:66
    #4  0x0403f1de in nxtask_startup (entrypt=0x40721b1 <hello_main>, argc=1, argv=0x40269628) at sched/task_startup.c:72
    #5  0x0400c66a in nxtask_start () at task/task_start.c:104
    #6  0x00000000 in ?? ()

Signed-off-by: yangao1 <yangao1@xiaomi.com>

libs/libc/machine/arm/armv7-a/arch_memcpy.S

@@ -164,6 +164,8 @@
 	.endm
 
 def_fn ARCH_LIBCFUN(memcpy) p2align=6
+	.cfi_sections .debug_frame
+	.cfi_startproc
 
 	mov	dst, dstin	/* Preserve dstin, we need to return it.  */
 	cmp	count, #64
@@ -627,6 +629,7 @@ def_fn ARCH_LIBCFUN(memcpy) p2align=6
 	bne	.Ltail63unaligned
 	bx	lr
 
+	.cfi_endproc
 	.size	ARCH_LIBCFUN(memcpy), . - ARCH_LIBCFUN(memcpy)
 
 #endif

libs/libc/machine/arm/armv7-a/arch_memmove.S

@@ -38,6 +38,8 @@
 	.global ARCH_LIBCFUN(memmove)
 	.type	ARCH_LIBCFUN(memmove), %function
 ARCH_LIBCFUN(memmove):
+	.cfi_sections .debug_frame
+	.cfi_startproc
 	cmp	r0, r1
 	push	{r4}
 	bls	3f
@@ -67,6 +69,7 @@ ARCH_LIBCFUN(memmove):
 	bne	4b
 	pop	{r4}
 	bx	lr
+	.cfi_endproc
 	.size ARCH_LIBCFUN(memmove), . - ARCH_LIBCFUN(memmove)
 
 #endif

libs/libc/machine/arm/armv7-a/arch_memset.S

@@ -38,6 +38,8 @@
 	.global ARCH_LIBCFUN(memset)
 	.type	ARCH_LIBCFUN(memset), %function
 ARCH_LIBCFUN(memset):
+	.cfi_sections .debug_frame
+	.cfi_startproc
 
 #ifdef __ARM_NEON__
 	mov         r3, r0
@@ -219,5 +221,6 @@ ARCH_LIBCFUN(memset):
 	ldmfd       sp!, {r0, r4-r7, pc}
 
 #endif
+	.cfi_endproc
 
 #endif