Auto merge of #115911 - nebulark:refactor_targetmachine, r=Nilstrieb

Add OwnedTargetMachine to manage llvm:TargetMachine

LLVMRustDisposeTargetMachine taking a &mut could be undefined behaviour.
Wrapping it with a struct and using pointers instead avoids this problem.
In addition the TargetMachine is now automatically freed via the Wrappers drop impl. This should fix some memory leaks when
create_informational_target_machine was used, e.g. https://github.com/rust-lang/rust/blob/327e6cf55cc5211e19ed46e92e05eef29dc75dd0/compiler/rustc_codegen_llvm/src/llvm_util.rs#L291-L314

r? `@Nilstrieb`

1 files changed, 6 insertions, 0 deletions

diff --git a/compiler/rustc_data_structures/src/small_c_str.rs b/compiler/rustc_data_structures/src/small_c_str.rs
index 719e4e3d974..349fd7f9769 100644
--- a/compiler/rustc_data_structures/src/small_c_str.rs
+++ b/compiler/rustc_data_structures/src/small_c_str.rs
@@ -79,3 +79,9 @@ impl<'a> FromIterator<&'a str> for SmallCStr {
         Self { data }
     }
 }
+
+impl From<&ffi::CStr> for SmallCStr {
+    fn from(s: &ffi::CStr) -> Self {
+        Self { data: SmallVec::from_slice(s.to_bytes()) }
+    }
+}