[parser] Better error message for missing number exponent (#12072)

* fix(babel-parser) better error message for missing number exponent after 'e'

* fix(babel-parser) requested changes

* msg

Co-authored-by: Brian Ng <bng412@gmail.com>

packages/babel-parser/src/tokenizer/index.js

@@ -1149,7 +1149,9 @@ export default class Tokenizer extends ParserErrors {
       if (next === charCodes.plusSign || next === charCodes.dash) {
         ++this.state.pos;
       }
-      if (this.readInt(10) === null) this.raise(start, Errors.InvalidNumber);
+      if (this.readInt(10) === null) {
+        this.raise(start, Errors.InvalidOrMissingExponent);
+      }
       isFloat = true;
       hasExponent = true;
       next = this.input.charCodeAt(this.state.pos);