8004051: assert(_oprs_len[mode] < maxNumberOfOperands) failed: array overflow

Summary: assert is triggered when number of register based arguments passed to a java method exceeds 16.
Reviewed-by: roland, vladidan

src/share/vm/c1/c1_LIR.hpp

@@ -2259,7 +2259,7 @@ class LIR_OpVisitState: public StackObj {
   typedef enum { inputMode, firstMode = inputMode, tempMode, outputMode, numModes, invalidMode = -1 } OprMode;
 
   enum {
-    maxNumberOfOperands = 16,
+    maxNumberOfOperands = 20,
     maxNumberOfInfos = 4
   };