This removes the need to manually rename columns for each separate context.
Instead, each operation's config now implements From<EccConfig>, providing
a derivation from the top-level configuration.

This allows fixed-base scalar mul to return (0,0) for [0]B.

Add tests to check that points related by the cubic endomorphism are
not constrained to add up to (0,0).

Co-authored-by: Jack Grigg <jack@electriccoin.co>

The EccConfig only knows about 10 generic advice columns. These
columns are renamed by individual components (e.g. AddConfig,
MulConfig). The mapping for each individual config is captured
in its impl From<EccConfig>.

…requires a doubling.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>

…on that requires a doubling.

Signed-off-by: Daira Hopwood <daira@jacaranda.org>

Inline equality assertions on values to individual components
(flagged off with #[cfg(test)].

Move module-specific tests into respective modules.

…pes.

We do not load the fixed bases into a single location in the circuit;
rather, they are assigned to fixed columns at the offsets where they
need to be used.

The EccLoaded struct was not storing any references to circuit variables.
It was holding constants in memory which the caller can instead directly
access.

Similarly, there is no need to have the FixedPoint or FixedPointShort
associated types in the EccInstructions trait, since these types do not
contain references to circuit variables. The corresponding get_fixed()
and get_fixed_short() instructions are also removed.

This was defining shared behaviour between the mul_fixed::short and
mul_fixed::full_width modules. But the behaviour can be captured by
simply sharing the same mul_fixed::Config.

There is no need to enumerate FixedPointsShort or to make a newtype,
since ValueCommitV is the only fixed base used with short signed
scalars.

…nfigs

…vs. short scalars

Tests do not always use the MockProver.