LibC: Define function sizes for setjmp and longjmp

dynamic linking was complaining about these not existing

userspace/libraries/LibC/arch/i686/setjmp.S

@@ -13,6 +13,8 @@ setjmp:
 
 	ret
 
+ .size setjmp, . - setjmp
+
 // void longjmp(jmp_buf env, int val)
 .global longjmp
 longjmp:
@@ -26,3 +28,5 @@ longjmp:
 	movl 0(%edx), %esp
 	movl 4(%edx), %ecx
 	jmp *%ecx
+
+ .size longjmp, . - longjmp

userspace/libraries/LibC/arch/x86_64/setjmp.S

@@ -10,6 +10,7 @@ setjmp:
 	xorq %rax, %rax
 
 	ret
+ .size setjmp, . - setjmp
 
 // void longjmp(jmp_buf env, int val)
 .global longjmp
@@ -21,3 +22,4 @@ longjmp:
 	movq 0(%rdi), %rsp
 	movq 8(%rdi), %rcx
 	jmp *%rcx
+ .size longjmp, . - longjmp