Merge #220: Add build profile 'release-smaller'

ba71a7a Add build profile 'release-smaller' (Steve Myers)

Pull request description:

  ### Description

  New profile turns on all the non-experimental rust build size optimizations.

  ### Notes to the reviewers

  This PR is the first step to fixing bitcoindevkit/bdk-swift#25.

  ### Changelog notice

  None.

  ### Checklists

  #### All Submissions:

  * [x] I've signed all my commits
  * [x] I followed the [contribution guidelines](https://github.com/bitcoindevkit/bdk/blob/master/CONTRIBUTING.md)
  * [x] I ran `cargo fmt` and `cargo clippy` before committing

ACKs for top commit:
  thunderbiscuit:
    ACK [ba71a7a](ba71a7a).

Tree-SHA512: b12cf3a3ad3683dccbb89f611e98246db4a604b674077a45b78e30e9e20021f443dfec68e8ab511e0bb64d84c5c7064b4078b578fc3b4c1fb2e1119680a656a6

Author: notmandatory

Cargo.toml

@@ -22,3 +22,11 @@ uniffi = { version = "0.21.0", features = ["builtin-bindgen"] }
 
 [build-dependencies]
 uniffi_build = { version = "0.21.0", features = ["builtin-bindgen"] }
+
+[profile.release-smaller]
+inherits = "release"
+opt-level = 'z'     # Optimize for size.
+lto = true          # Enable Link Time Optimization
+codegen-units = 1   # Reduce number of codegen units to increase optimizations.
+panic = 'abort'     # Abort on panic
+strip = true        # Strip symbols from binary*