Minor cleanup for kani-compiler (rust-lang#2263)

Cargo.lock

@@ -497,7 +497,6 @@ version = "0.22.0"
 dependencies = [
  "ar",
  "atty",
- "bitflags",
  "clap",
  "cprover_bindings",
  "home",

kani-compiler/Cargo.toml

@@ -11,7 +11,6 @@ publish = false
 [dependencies]
 ar = { version = "0.9.0", optional = true }
 atty = "0.2.14"
-bitflags = { version = "1.0", optional = true }
 cbmc = { path = "../cprover_bindings", package = "cprover_bindings", optional = true }
 clap = { version = "4.1.3", features = ["cargo"] }
 home = "0.5"
@@ -36,7 +35,7 @@ tracing-tree = "0.2.2"
 # Future proofing: enable backend dependencies using feature.
 [features]
 default = ['cprover']
-cprover = ['ar', 'bitflags', 'cbmc', 'libc', 'num', 'object', 'rustc-demangle', 'serde',
+cprover = ['ar', 'cbmc', 'libc', 'num', 'object', 'rustc-demangle', 'serde',
     'serde_json', "strum", "strum_macros"]
 unsound_experiments = ["kani_queries/unsound_experiments"]
 

kani-compiler/src/codegen_cprover_gotoc/compiler_interface.rs

@@ -12,7 +12,6 @@ use crate::kani_middle::provide;
 use crate::kani_middle::reachability::{
     collect_reachable_items, filter_closures_in_const_crate_items, filter_crate_items,
 };
-use bitflags::_core::any::Any;
 use cbmc::goto_program::Location;
 use cbmc::{InternedString, MachineModel};
 use kani_metadata::CompilerArtifactStub;
@@ -39,6 +38,7 @@ use rustc_session::Session;
 use rustc_span::def_id::DefId;
 use rustc_target::abi::Endian;
 use rustc_target::spec::PanicStrategy;
+use std::any::Any;
 use std::collections::BTreeMap;
 use std::ffi::OsString;
 use std::fmt::Write;

kani-compiler/src/kani_compiler.rs

@@ -15,6 +15,7 @@
 //! in order to apply the stubs. For the subsequent runs, we add the stub configuration to
 //! `-C llvm-args`.
 
+#[cfg(feature = "cprover")]
 use crate::codegen_cprover_gotoc::GotocCodegenBackend;
 use crate::kani_middle::stubbing;
 use crate::parser::{self, KaniCompilerParser};