Make jerryx_port_handler_print_char truly a port function (#2789)

In the previous approach `jerryx_port_handler_print_char` was implemented
in by the jerry-default-port. This implementation however required the
jerry-ext handler header file which created a requirement in the
jerry-default-port for the jerry-ext headers.

JerryScript-DCO-1.0-Signed-off-by: Peter Gal pgal.u-szeged@partner.samsung.com

docs/05.PORT-API.md

@@ -72,6 +72,18 @@ typedef enum
 void jerry_port_log (jerry_log_level_t level, const char *fmt, ...);
 ```
 
+The `jerry_port_print_char` is currenlty not used by the jerry-core directly.
+However, it provides a port specifc way for `jerry-ext` components to print
+information.
+
+```c
+/**
+ * Print a character to stdout.
+ */
+void jerry_port_print_char (char c);
+```
+
+
 ## Date
 
 ```c
@@ -201,6 +213,17 @@ jerry_port_log (jerry_log_level_t level, /**< log level */
 } /* jerry_port_log */
 ```
 
+```c
+/**
+ * Print a character to stdout with putchar.
+ */
+void
+jerry_port_print_char (char c)
+{
+  putchar (c);
+} /* jerr_port_print_char */
+```
+
 ## Date
 
 ```c

docs/10.EXT-REFERENCE-HANDLER.md

@@ -97,14 +97,14 @@ jerryx_handler_gc (const jerry_value_t func_obj_val, const jerry_value_t this_p,
 
 Provide a `print` implementation for scripts. The routine converts all of its
 arguments to strings and outputs them char-by-char using
-`jerryx_port_handler_print_char`. The NUL character is output as "\u0000",
+`jerry_port_print_char`. The NUL character is output as "\u0000",
 other characters are output bytewise.
 
 *Note*: This implementation does not use standard C `printf` to print its
 output. This allows more flexibility but also extends the core JerryScript
 engine port API. Applications that want to use `jerryx_handler_print` must
 ensure that their port implementation also provides
-`jerryx_port_handler_print_char`.
+`jerry_port_print_char`.
 
 **Prototype**
 
@@ -124,7 +124,7 @@ jerryx_handler_print (const jerry_value_t func_obj_val, const jerry_value_t this
 **See also**
 
 - [jerryx_handler_register_global](#jerryx_handler_register_global)
-- [jerryx_port_handler_print_char](#jerryx_port_handler_print_char)
+- [jerry_port_print_char](05.PORT-API.md#jerry_port_print_char)
 
 
 # Handler registration helper
@@ -184,38 +184,3 @@ register_common_functions (void)
   jerry_release_value (ret);
 }
 ```
-
-
-# Port API extension
-
-## jerryx_port_handler_print_char
-
-**Summary**
-
-Print a single character.
-
-**Prototype**
-
-```c
-void
-jerryx_port_handler_print_char (char c);
-```
-
-- `c` - the character to print.
-
-**Example**
-
-```c
-/**
- * Print a character to stdout with printf.
- */
-void
-jerryx_port_handler_print_char (char c)
-{
-  printf ("%c", c);
-} /* jerryx_port_handler_print_char */
-```
-
-**See also**
-
-- [jerryx_handler_print](#jerryx_handler_print)