The $value$plusargs() routine can put to a two-state variable.

Update the $value_plusargs() routine so it can put the extracted value
to a two-state variable.

vpi/sys_plusargs.c

@@ -109,6 +109,11 @@ static PLI_INT32 sys_value_plusargs_compiletf(ICARUS_VPI_CONST PLI_BYTE8*name)
 
 	  case vpiReg:
 	  case vpiIntegerVar:
+	  case vpiBitVar:
+	  case vpiByteVar:
+	  case vpiShortIntVar:
+	  case vpiIntVar:
+	  case vpiLongIntVar:
 	  case vpiRealVar:
 	  case vpiTimeVar:
 	    break;