Use node's builtin assert in the JS compiler. NFC (#17469)

Node's assert message are way nicer too.

Author: sbc100

src/compiler.js

@@ -8,6 +8,7 @@
 // LLVM => JavaScript compiler, main entry point
 
 const fs = require('fs');
+global.assert = require('assert');
 global.nodePath = require('path');
 
 global.print = (x) => {

src/utility.js

@@ -39,15 +39,6 @@ function dump(item) {
   }
 }
 
-function assert(a, msg) {
-  if (!a) {
-    msg = 'Assertion failed' + (msg ? ': ' + msg : '');
-    print(msg);
-    printErr('Stack: ' + new Error().stack);
-    throw msg;
-  }
-}
-
 global.warnings = false;
 
 function warn(a, msg) {

tools/preprocessor.js

@@ -27,6 +27,8 @@ global.printErr = function(x) {
   process['stderr'].write(x + '\n');
 };
 
+global.assert = require('assert');
+
 function find(filename) {
   const prefixes = [process.cwd(), path.join(__dirname, '..', 'src')];
   for (let i = 0; i < prefixes.length; ++i) {