Added opcodes for arithmetic with K operands

Added opcodes for all seven arithmetic operators with K operands
(that is, operands that are numbers in the array of constants of
the function). They cover the cases of constant float operands
(e.g., 'x + .0.0', 'x^0.5') and large integer operands (e.g.,
'x % 10000').

lopnames.h

@@ -36,6 +36,13 @@ static const char *const opnames[] = {
   "POWI",
   "DIVI",
   "IDIVI",
+  "ADDK",
+  "SUBK",
+  "MULK",
+  "MODK",
+  "POWK",
+  "DIVK",
+  "IDIVK",
   "BANDK",
   "BORK",
   "BXORK",