v0.18.0

In addition to lots of (still very WIP) progress towards our goal of automatic safening of c2rust's unsafe output, this release also includes:

a bug fix for compile_commands.json handling (3f4f12850e756b8cbd3822a12bf5bf7348b05206)
fixes for LLVM 17 and macOS 12 (e1043cd549849ebf89ca7af179deb6574209057d)
a crash fix for c2rust-ast-exporter (5b9800a9a18191ee990c45f367f76c3cf323c6fc)
fixes for unary operations with side effects (f9c51950732bb47dfae5c35223e9955d203ba846)
compilation fixes for freebsd (abe22f6b69061106a4c68938a908c50651ba959f)
improved translation for else-if chains (d467a76bc4172e5e47332ab320f7a78ca7055a53)
transpilation fixes for many compiler builtins (5b097bbd03f372b4b975d2181867f76def021510)

In addition to lots of (still very WIP) progress towards our goal of automatic safening of c2rust's unsafe output, this release also includes:

a bug fix for compile_commands.json handling (3f4f12850e756b8cbd3822a12bf5bf7348b05206)
fixes for LLVM 17 and macOS 12 (e1043cd549849ebf89ca7af179deb6574209057d)
a crash fix for c2rust-ast-exporter (5b9800a9a18191ee990c45f367f76c3cf323c6fc)
fixes for unary operations with side effects (f9c51950732bb47dfae5c35223e9955d203ba846)
compilation fixes for freebsd (abe22f6b69061106a4c68938a908c50651ba959f)
improved translation for else-if chains (d467a76bc4172e5e47332ab320f7a78ca7055a53)
transpilation fixes for many compiler builtins (5b097bbd03f372b4b975d2181867f76def021510)

c2rust