Convert Unicode procedures to stdcall convention.

1. Use cinvoke macro instead of invoke for con_printf
2. Convert `end:` to `P_END:`, As the previous one was a FASM keyword
3. Upgrade all functions in libunicode.asm to use stdcall convention

programs/develop/libraries/libunicode/libunicode.asm

@@ -29,16 +29,13 @@ section '.flat' code readable align 16
 ;=============================================================
 ;   CodePoint Counting function
 ;   Parameters:
-;       eax = pointer to the memory address of the null
+;       _str_ptr = pointer to the memory address of the null
 ;             terminated string
 ;   Return values:
 ;       eax = total codepoints
-;   -------PRIVATE--------
-;   ebx <- counter of codepoints
-;   ecx <- each byte
-;   
 ;=============================================================
-proc count_utf8_codepoints
+proc count_utf8_codepoints uses ebx, _str_ptr
+        mov     eax, [_str_ptr]
         mov     ebx, 0
 
 .read_loop:
@@ -61,14 +58,15 @@ proc count_utf8_codepoints
 endp
 
 ;=============================================================
-;   eax <- pointer to the memory address of the string
-;   * Do not use other register because it may be overwritten.
-;   -------PRIVATE--------
-;   ebx <- counter of grapheme
-;   ecx <- each byte
-;   
+;   Grapheme Counting function
+;   Parameters:
+;       _str_ptr = pointer to the memory address of the null
+;             terminated string
+;   Return values:
+;       eax = total grapheme count
 ;=============================================================
-proc count_utf8_graphemes
+proc count_utf8_graphemes uses ebx, _str_ptr
+        mov     eax, [_str_ptr]
         mov     ebx, 0
 
 .read_loop: