Move lengthBytesUTF8 into runtime. NFC. (#12825)

It doesn't seems to be needed at parse time.

src/parseTools.js

@@ -945,22 +945,6 @@ function charCode(char) {
   return char.charCodeAt(0);
 }
 
-// Returns the number of bytes the given Javascript string takes if encoded as a UTF8 byte array, EXCLUDING the null terminator byte.
-function lengthBytesUTF8(str) {
-  var len = 0;
-  for (var i = 0; i < str.length; ++i) {
-    // Gotcha: charCodeAt returns a 16-bit word that is a UTF-16 encoded code unit, not a Unicode code point of the character! So decode UTF16->UTF32->UTF8.
-    // See http://unicode.org/faq/utf_bom.html#utf16-3
-    var u = str.charCodeAt(i); // possibly a lead surrogate
-    if (u >= 0xD800 && u <= 0xDFFF) u = 0x10000 + ((u & 0x3FF) << 10) | (str.charCodeAt(++i) & 0x3FF);
-    if (u <= 0x7F) ++len;
-    else if (u <= 0x7FF) len += 2;
-    else if (u <= 0xFFFF) len += 3;
-    else len += 4;
-  }
-  return len;
-}
-
 function getTypeFromHeap(suffix) {
   switch (suffix) {
     case '8': return 'i8';

src/runtime_strings.js

@@ -190,4 +190,17 @@ function stringToUTF8(str, outPtr, maxBytesToWrite) {
 }
 
 // Returns the number of bytes the given Javascript string takes if encoded as a UTF8 byte array, EXCLUDING the null terminator byte.
-{{{ lengthBytesUTF8 }}}
+function lengthBytesUTF8(str) {
+  var len = 0;
+  for (var i = 0; i < str.length; ++i) {
+    // Gotcha: charCodeAt returns a 16-bit word that is a UTF-16 encoded code unit, not a Unicode code point of the character! So decode UTF16->UTF32->UTF8.
+    // See http://unicode.org/faq/utf_bom.html#utf16-3
+    var u = str.charCodeAt(i); // possibly a lead surrogate
+    if (u >= 0xD800 && u <= 0xDFFF) u = 0x10000 + ((u & 0x3FF) << 10) | (str.charCodeAt(++i) & 0x3FF);
+    if (u <= 0x7F) ++len;
+    else if (u <= 0x7FF) len += 2;
+    else if (u <= 0xFFFF) len += 3;
+    else len += 4;
+  }
+  return len;
+}