Add print_int32 (support for negative numbers)

Closed #2

src/data/logger.asm

@@ -1,6 +1,7 @@
 char_newline      db 0x0a
 char_space        db 0x20
 char_dot          db '.'
+char_minus        db '-'
 char_single_quote db 0x27
 char_double_quote db 0x22
 

src/logger.asm

@@ -13,6 +13,18 @@ print_newline:
     pop_registers
     ret
 
+print_minus:
+    push_registers
+
+    mov rax, SYS_WRITE
+    mov rdi, STDOUT
+    mov rsi, char_minus
+    mov rdx, 1
+    syscall
+
+    pop_registers
+    ret
+
 print_single_quote:
     push_registers
 
@@ -67,6 +79,18 @@ dbg_print_uint32:
 
     ret
 
+
+print_int32:
+    ; print_int32 [rax]
+    cmp rax, 0
+    jge .print_int32_positive
+.print_int32_negative:
+    call print_minus
+    neg rax
+.print_int32_positive:
+    call print_uint32
+    ret
+
 print_uint32:
     ; print_uint32 [rax]
     ;