Add some missing cfi frame info in x25519-x86_64.pl

Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NKurt Roeckx <kurt@roeckx.be>
(Merged from https://github.com/openssl/openssl/pull/10676)

(cherry picked from commit 9d079f2744b9b624c6fe75f95fc0f766ef88ffcf)

crypto/ec/asm/x25519-x86_64.pl

@@ -488,12 +488,14 @@ $code.=<<___;
 .type	x25519_fe64_eligible,\@abi-omnipotent
 .align	32
 x25519_fe64_eligible:
+.cfi_startproc
 	mov	OPENSSL_ia32cap_P+8(%rip),%ecx
 	xor	%eax,%eax
 	and	\$0x80100,%ecx
 	cmp	\$0x80100,%ecx
 	cmove	%ecx,%eax
 	ret
+.cfi_endproc
 .size	x25519_fe64_eligible,.-x25519_fe64_eligible
 
 .globl	x25519_fe64_mul
@@ -722,6 +724,7 @@ x25519_fe64_sqr:
 .align	32
 x25519_fe64_mul121666:
 .Lfe64_mul121666_body:
+.cfi_startproc
 	mov	\$121666,%edx
 	mulx	8*0(%rsi),$acc0,%rcx
 	mulx	8*1(%rsi),$acc1,%rax
@@ -750,6 +753,7 @@ x25519_fe64_mul121666:
 
 .Lfe64_mul121666_epilogue:
 	ret
+.cfi_endproc
 .size	x25519_fe64_mul121666,.-x25519_fe64_mul121666
 
 .globl	x25519_fe64_add
@@ -757,6 +761,7 @@ x25519_fe64_mul121666:
 .align	32
 x25519_fe64_add:
 .Lfe64_add_body:
+.cfi_startproc
 	mov	8*0(%rsi),$acc0
 	mov	8*1(%rsi),$acc1
 	mov	8*2(%rsi),$acc2
@@ -785,6 +790,7 @@ x25519_fe64_add:
 
 .Lfe64_add_epilogue:
 	ret
+.cfi_endproc
 .size	x25519_fe64_add,.-x25519_fe64_add
 
 .globl	x25519_fe64_sub
@@ -792,6 +798,7 @@ x25519_fe64_add:
 .align	32
 x25519_fe64_sub:
 .Lfe64_sub_body:
+.cfi_startproc
 	mov	8*0(%rsi),$acc0
 	mov	8*1(%rsi),$acc1
 	mov	8*2(%rsi),$acc2
@@ -820,6 +827,7 @@ x25519_fe64_sub:
 
 .Lfe64_sub_epilogue:
 	ret
+.cfi_endproc
 .size	x25519_fe64_sub,.-x25519_fe64_sub
 
 .globl	x25519_fe64_tobytes
@@ -827,6 +835,7 @@ x25519_fe64_sub:
 .align	32
 x25519_fe64_tobytes:
 .Lfe64_to_body:
+.cfi_startproc
 	mov	8*0(%rsi),$acc0
 	mov	8*1(%rsi),$acc1
 	mov	8*2(%rsi),$acc2
@@ -862,6 +871,7 @@ x25519_fe64_tobytes:
 
 .Lfe64_to_epilogue:
 	ret
+.cfi_endproc
 .size	x25519_fe64_tobytes,.-x25519_fe64_tobytes
 ___
 } else {
@@ -870,8 +880,10 @@ $code.=<<___;
 .type	x25519_fe64_eligible,\@abi-omnipotent
 .align	32
 x25519_fe64_eligible:
+.cfi_startproc
 	xor	%eax,%eax
 	ret
+.cfi_endproc
 .size	x25519_fe64_eligible,.-x25519_fe64_eligible
 
 .globl	x25519_fe64_mul
@@ -887,8 +899,10 @@ x25519_fe64_mul121666:
 x25519_fe64_add:
 x25519_fe64_sub:
 x25519_fe64_tobytes:
+.cfi_startproc
 	.byte	0x0f,0x0b	# ud2
 	ret
+.cfi_endproc
 .size	x25519_fe64_mul,.-x25519_fe64_mul
 ___
 }