Spent the afternoon hassling with this "unrecognized
command" bug (#1112782), until I finally found that there
are TWO settings that must be disabled in order to
remove it.
The first is in Tools->Compiler Options->Settings->C++
Compiler->"Use Heuristics..." = NO.
The second is in Project->Project Options->Compiler-
C++ Compiler->"Use Heuristics..."=NO.
I have tried running CC1PLUS.exe from the command
line with -fsave-memoized and got the error message for
both the version 3.4.2, and version 4.0.0(djpp).
REQUEST FOR ENHANCEMENT: Maybe this feature
("Use Heuristics") could be converted to a NOP for the
next update, or removed entirely if it is a depreciated
feature, as it doesn't currently work with the included
compiler.