Don't use strlen for string literals (#2517)

Their length (size) is known at compile time. Therefore `sizeof`
is more efficient for them.

JerryScript-DCO-1.0-Signed-off-by: Akos Kiss akiss@inf.u-szeged.hu

docs/07.DEBUGGER.md

@@ -251,7 +251,6 @@ jerry_debugger_stop_at_breakpoint (bool enable_stop_at_breakpoint)
 [doctest]: # (test="link")
 
 ```c
-#include <string.h>
 #include "jerryscript.h"
 #include "jerryscript-ext/debugger.h"
 
@@ -266,8 +265,7 @@ main (void)
 
   // Protected execution of JavaScript code.
   const jerry_char_t script[] = "42";
-  size_t script_size = strlen ((const char *) script);
-  jerry_eval (script, script_size, JERRY_PARSE_NO_OPTS);
+  jerry_eval (script, sizeof (script) - 1, JERRY_PARSE_NO_OPTS);
 
   jerry_debugger_stop_at_breakpoint (false);