Chore/anchor 32

[jordy25519]

Changes

• any structs with zero_copy(unsafe) and u/i128 fields are now marked with legacy_layout macro (rewrites definition to use compat::u128/i128 + adds getter/setters with internal conversions to/from std::primitive types)
• anchor_lang::Discriminator changed to use &[u8] instead of [u8; 8]

Notes

• newly created accounts should be safe to create with i/u128 fields without the macro
• devs should be aware of the u128/i128 math now needing an extra conversion. prefer using getter/setter over raw field accessself.scaled_balance()
• an idl-build feature is required in Cargo.tomls for IDL build from now on and added to all deps involved

Complementary PRs

• add legacy_layout macro to help rewrite zero-copy structs with u/i128… drift-macros#1

• anchor v32 phoenix-v1#1

• anchor 0.32 update pyth-crosschain#8

• drift-labs/serum-dex@2347e48

• part 1: Chore/anchor 32 #2019