Make debug builds more useful & testing faster. (#4807)

* Make debug builds more useful & testing likely faster.

Stolen from substrate.

* Add some more packages from

https://github.com/paritytech/polkadot/pull/3344/files

* Fix compilation.

polkadot/Cargo.toml

@@ -121,6 +121,61 @@ exclude = ["bridges/relays/bin-substrate", "bridges/bin/rialto/runtime", "bridge
 [badges]
 maintenance = { status = "actively-developed" }
 
+# The list of dependencies below (which can be both direct and indirect dependencies) are crates
+# that are suspected to be CPU-intensive, and that are unlikely to require debugging (as some of
+# their debug info might be missing) or to require to be frequently recompiled. We compile these
+# dependencies with `opt-level=3` even in "dev" mode in order to make "dev" mode more usable.
+# The majority of these crates are cryptographic libraries.
+#
+# If you see an error mentioning "profile package spec ... did not match any packages", it
+# probably concerns this list.
+#
+# This list is ordered alphabetically.
+[profile.dev.package]
+blake2b_simd = { opt-level = 3 }
+blake2 = { opt-level = 3 }
+blake2-rfc = { opt-level = 3 }
+chacha20poly1305 = { opt-level = 3 }
+cranelift-codegen = { opt-level = 3 }
+cranelift-wasm = { opt-level = 3 }
+crc32fast = { opt-level = 3 }
+crossbeam-deque = { opt-level = 3 }
+crypto-mac = { opt-level = 3 }
+curve25519-dalek = { opt-level = 3 }
+ed25519-dalek = { opt-level = 3 }
+flate2 = { opt-level = 3 }
+futures-channel = { opt-level = 3 }
+hashbrown = { opt-level = 3 }
+hash-db = { opt-level = 3 }
+hmac = { opt-level = 3 }
+httparse = { opt-level = 3 }
+integer-sqrt = { opt-level = 3 }
+keccak = { opt-level = 3 }
+libm = { opt-level = 3 }
+librocksdb-sys = { opt-level = 3 }
+libsecp256k1 = { opt-level = 3 }
+libz-sys = { opt-level = 3 }
+mio = { opt-level = 3 }
+nalgebra = { opt-level = 3 }
+num-bigint = { opt-level = 3 }
+parking_lot_core = { opt-level = 3 }
+parking_lot = { opt-level = 3 }
+percent-encoding = { opt-level = 3 }
+primitive-types = { opt-level = 3 }
+reed-solomon-novelpoly = { opt-level = 3 }
+ring = { opt-level = 3 }
+rustls = { opt-level = 3 }
+sha2 = { opt-level = 3 }
+sha3 = { opt-level = 3 }
+smallvec = { opt-level = 3 }
+snow = { opt-level = 3 }
+twox-hash = { opt-level = 3 }
+uint = { opt-level = 3 }
+wasmi = { opt-level = 3 }
+x25519-dalek = { opt-level = 3 }
+yamux = { opt-level = 3 }
+zeroize = { opt-level = 3 }
+
 [profile.release]
 # Polkadot runtime requires unwinding.
 panic = "unwind"
@@ -181,3 +236,4 @@ polkadot = { path = "/usr/bin/polkadot" }
 
 [package.metadata.spellcheck]
 config = "./scripts/gitlab/spellcheck.toml"
+