Fix dart2js decimal number tokenization.

sdk/lib/_internal/compiler/implementation/scanner/scanner.dart

Index: sdk/lib/_internal/compiler/implementation/scanner/scanner.dart
diff --git a/sdk/lib/_internal/compiler/implementation/scanner/scanner.dart b/sdk/lib/_internal/compiler/implementation/scanner/scanner.dart
index 75b9cb507c720ee36b6310a5255b6768b24a3e8d..4503fa872a809b75a234c8a973a6f7a979f99f95 100644
--- a/sdk/lib/_internal/compiler/implementation/scanner/scanner.dart
+++ b/sdk/lib/_internal/compiler/implementation/scanner/scanner.dart
@@ -462,12 +462,13 @@ abstract class AbstractScanner<T extends SourceString> implements Scanner {
     int start = byteOffset;
     while (true) {
       next = advance();
+      int nextnext = peek();

[ahe, 2013/09/06 14:20:26]

Can you avoid calling peek until you see a '.'?

       if ($0 <= next && next <= $9) {
         continue;
-      } else if (identical(next, $PERIOD)) {
+      } else if (identical(next, $PERIOD)

[ahe, 2013/09/06 14:20:26]

Would this work:

} else if (identical(next, $PERIOD)) {
  int nextnext = peek();
  if ($0 <= nextnext && nextnext <= $9) {
    return tokenizeFractionPart(advance(), start);
  }
  appendByteStringToken(INT_INFO, asciiString(start, 0));
  return next;
} else if ...

This duplicates code, but reduces look-ahead.

+                  && ($0 <= nextnext && nextnext <= $9)) {
         return tokenizeFractionPart(advance(), start);
-      } else if (identical(next, $e) || identical(next, $E)
-          || identical(next, $d) || identical(next, $D)) {
+      } else if (identical(next, $e) || identical(next, $E)) {
         return tokenizeFractionPart(next, start);
       } else {
         appendByteStringToken(INT_INFO, asciiString(start, 0));
@@ -543,9 +544,6 @@ abstract class AbstractScanner<T extends SourceString> implements Scanner {
       appendPrecedenceToken(PERIOD_INFO);
       return bigSwitch(next);
     }
-    if (identical(next, $d) || identical(next, $D)) {
-      next = advance();
-    }
     appendByteStringToken(DOUBLE_INFO, asciiString(start, 0));
     return next;
   }