ensure_smint tested for DTYPE_SMINT and then cast to DTYPE_INT. It was the only
one of the twelve ensure_* functions that casts to a different type from the one
it just tested for, so a value coerced for a SMALLINT parameter arrived as an
INTEGER. C did not care - the two interconvert silently - but a back end with a
distinct 16-bit type cannot pass the result to the parameter it was coerced for.
Also: 4GL says SMALLINT minus a literal is still SMALLINT, so no conversion was
requested. That holds for the 4GL type but not for the expression a back end
writes to evaluate it - C and C# both promote short arithmetic to int, and the
result has to be narrowed again before it can be passed to a SMALLINT
parameter. ensure_smint now asks for the cast on arithmetic, looking through
brackets so "(a - 1)" is treated like "a - 1".
make_cast took a "force" flag and never consulted it, so a cast that is a no-op
by 4GL type rules could not be requested even where a back end needs it written
out. It is now honoured, and ensure_smint uses it for the case above.
No change to the C back end's output on the example suite.
