utf8: remove unused UTF8_CHAR_LEN macro and add a simple utf8 test

compiler/main.v

@@ -229,13 +229,12 @@ typedef map map_string;
 	#define false 0
 #endif
 
-//============================== HELPER C.MACROS =============================*/ 
+//============================== HELPER C MACROS =============================*/ 
 
 #define _PUSH(arr, val, tmp, tmp_typ) {tmp_typ tmp = (val); array__push(arr, &tmp);}
 #define _PUSH_MANY(arr, val, tmp, tmp_typ) {tmp_typ tmp = (val); array__push_many(arr, tmp.data, tmp.len);}
 #define _IN(typ, val, arr) array_##typ##_contains(arr, val) 
 #define ALLOC_INIT(type, ...) (type *)memdup((type[]){ __VA_ARGS__ }, sizeof(type)) 
-#define UTF8_.chartoken_.leN( byte ) (( 0xE5000000 >> (( byte >> 3 ) & 0x1e )) & 3 ) + 1 
 
 //================================== GLOBALS =================================*/   
 //int V_ZERO = 0; 

compiler/parser.v

@@ -3017,7 +3017,7 @@ fn (p mut Parser) assert_statement() {
 	filename := p.file_path
 	p.genln(';\n 
 if (!$tmp) { 
-  puts("\\x1B[31mFAI.leD: $p.cur_fn.name() in $filename:$p.scanner.line_nr\\x1B[0m");  
+  puts("\\x1B[31mFAILED: $p.cur_fn.name() in $filename:$p.scanner.line_nr\\x1B[0m");  
 g_test_ok = 0 ; 
 	// TODO
 	// Maybe print all vars in a test function if it fails? 

vlib/builtin/utf8_test.v

@@ -0,0 +1,5 @@
+fn test_utf8_char_len() {
+	assert utf8_char_len(`a`) == 1 
+	s := 'п' 
+	assert utf8_char_len(s[0]) == 2 
+}