fac30eec42 refactor: Replace &foo[0] with foo.data() (MarcoFalke)
faece47c47 refactor: Avoid &foo[0] on C-Style arrays (MarcoFalke)
face961109 refactor: Use only one temporary buffer in CreateObfuscateKey (MarcoFalke)
fa05dddc42 refactor: Use CPubKey vector constructor where possible (MarcoFalke)
fabb6dfe6e script: Replace address-of idiom with vector data() method (Guido Vranken)
Pull request description:
The main theme of this refactor is to replace `&foo[0]` with `foo.data()`.
The first commit is taken from #21781 with the rationale:
* In CSignatureCache::ComputeEntryECDSA, change the way a vector pointer is resolved to prevent invoking undefined behavior if the vector is empty.
The other commits aim to remove all `&foo[0]`, where `foo` is any kind of byte representation. The rationale:
* Sometimes alternative code without any raw data pointers is easier to read (refer to the respective commit message for details)
* If the raw data pointer is needed, `foo.data()` should be preferred, as pointed out in the developer notes. This addresses the instances that have been missed in commit 592404f03f, and https://github.com/bitcoin/bitcoin/pull/9804
ACKs for top commit:
laanwj:
Code review ACK fac30eec42
practicalswift:
cr ACK fac30eec42: patch looks correct
promag:
Code review ACK fac30eec42.
Tree-SHA512: e7e73146edbc78911a8e8c728b0a1c6b0ed9a88a008e650aa5dbffe72425bd42c76df70199a9cf7e02637448d7593e0eac52fd0f91f59240283e1390ee21bfa5