- Added a RETI instruction for returning 15-bit signed immediate values.

- Changed Actor's Damage property into an actual function. All access to the damage property
  must now be done through GetMissileDamage. actor->GetMissileDamage(0, 1) is equivalent
  to the former actor->Damage, for the case where actor->Damage was not an expression. (I
  suppose I will probably need to make a thunk for DECORATE expressions that want to read it.)
- Cleaned up some decorate expression evaluation functions that are no longer used.

SVN r3919 (scripting)

src/zscript/vmbuilder.cpp

@@ -490,6 +490,27 @@ size_t VMFunctionBuilder::EmitLoadInt(int regnum, int value)
 	}
 }
 
+//==========================================================================
+//
+// VMFunctionBuilder :: EmitRetInt
+//
+// Returns an integer, using either an immediate value or a constant
+// register, as appropriate.
+//
+//==========================================================================
+
+size_t VMFunctionBuilder::EmitRetInt(int retnum, bool final, int value)
+{
+	if (value >= -16384 && value <= 16383)
+	{
+		return Emit(OP_RETI, retnum, value | (final << 15));
+	}
+	else
+	{
+		return Emit(OP_RETI, retnum, REGT_INT | REGT_KONST | (final ? REGT_FINAL : 0), GetConstantInt(value));
+	}
+}
+
 //==========================================================================
 //
 // VMFunctionBuilder :: Backpatch