fix JNI float argument passing

Floats are implicitly promoted to doubles when passed as part of a
variable-length argument list, so we can't treat them the same way as
32-bit integers.

src/compile.cpp

@@ -8037,10 +8037,17 @@ class ArgumentList {
         break;
       
       case 'J':
-      case 'D':
         addLong(va_arg(arguments, uint64_t));
         break;
 
+      case 'D':
+        addLong(doubleToBits(va_arg(arguments, double)));
+        break;
+
+      case 'F':
+        addInt(floatToBits(va_arg(arguments, double)));
+        break;
+
       default:
         addInt(va_arg(arguments, uint32_t));
         break;