Merge pull request #595 from 9rnsr/fix12813

Issue 12813 - Parser is confused between float and UFC syntax

lex.dd

@@ -689,6 +689,10 @@ $(GNAME HexDigitsNoSingleUS):
     $(GLINK HexDigit) $(GLINK HexDigitsUS)
     $(GLINK HexDigitsUS) $(GLINK HexDigit)
 
+$(GNAME HexDigitsNoStartingUS):
+    $(GLINK HexDigit)
+    $(GLINK HexDigit) $(GLINK HexDigitsUS)
+
 $(GNAME HexDigit):
     $(GLINK DecimalDigit)
     $(GLINK HexLetter)
@@ -791,7 +795,7 @@ $(GNAME Float):
 $(GNAME DecimalFloat):
     $(GLINK LeadingDecimal) $(B .)
     $(GLINK LeadingDecimal) $(B .) $(GLINK DecimalDigits)
-    $(GLINK DecimalDigits) $(B .) $(GLINK DecimalDigitsNoSingleUS) $(GLINK DecimalExponent)
+    $(GLINK DecimalDigits) $(B .) $(GLINK DecimalDigitsNoStartingUS) $(GLINK DecimalExponent)
     $(B .) $(GLINK DecimalInteger)
     $(B .) $(GLINK DecimalInteger) $(GLINK DecimalExponent)
     $(GLINK LeadingDecimal) $(GLINK DecimalExponent)
@@ -808,8 +812,8 @@ $(GNAME DecimalExponentStart)
     $(B E-)
 
 $(GNAME HexFloat):
-    $(GLINK HexPrefix) $(GLINK HexDigitsNoSingleUS) $(B .) $(GLINK HexDigitsNoSingleUS) $(GLINK HexExponent)
-    $(GLINK HexPrefix) $(B .) $(GLINK HexDigitsNoSingleUS) $(GLINK HexExponent)
+    $(GLINK HexPrefix) $(GLINK HexDigitsNoSingleUS) $(B .) $(GLINK HexDigitsNoStartingUS) $(GLINK HexExponent)
+    $(GLINK HexPrefix) $(B .) $(GLINK HexDigitsNoStartingUS) $(GLINK HexExponent)
     $(GLINK HexPrefix) $(GLINK HexDigitsNoSingleUS) $(GLINK HexExponent)
 
 $(GNAME HexPrefix):