Ignore <! when tokenizing JSX

Fixes #41

Author: RReverser

inject.js

@@ -411,7 +411,7 @@ module.exports = function(acorn) {
             return this.jsx_readString(code);
         }
 
-        if (code === 60 && this.exprAllowed) {
+        if (code === 60 && this.exprAllowed && this.input.charCodeAt(this.pos + 1) !== 33) {
           ++this.pos;
           return this.finishToken(tt.jsxTagStart);
         }

test/tests-jsx.js

@@ -3787,6 +3787,16 @@ test('<a>{/* foo */}</a>', {}, {
   ]
 });
 
+test('<!--a', {
+  type: 'Program',
+  body: []
+}, {
+  onComment: [{
+    type: 'Line',
+    value: 'a'
+  }]
+});
+
 for (var ns in fbTestFixture) {
   ns = fbTestFixture[ns];
   for (var code in ns) {