replace invocations of '.as_str()' with references

Author: JOE1994

Diff for: src/shims/env.rs

@@ -79,7 +79,7 @@ impl<'mir, 'tcx> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tc
 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
     fn getenv(&mut self, name_op: OpTy<'tcx, Tag>) -> InterpResult<'tcx, Scalar<Tag>> {
         let this = self.eval_context_mut();
-        let target_os = this.tcx.sess.target.target.target_os.as_str();
+        let target_os = &this.tcx.sess.target.target.target_os;
         assert!(target_os == "linux" || target_os == "macos", "`getenv` is only available for the UNIX target family");
 
         let name_ptr = this.read_scalar(name_op)?.not_undef()?;
@@ -179,7 +179,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
         value_op: OpTy<'tcx, Tag>,
     ) -> InterpResult<'tcx, i32> {
         let mut this = self.eval_context_mut();
-        let target_os = this.tcx.sess.target.target.target_os.as_str();
+        let target_os = &this.tcx.sess.target.target.target_os;
         assert!(target_os == "linux" || target_os == "macos", "`setenv` is only available for the UNIX target family");
 
         let name_ptr = this.read_scalar(name_op)?.not_undef()?;
@@ -252,7 +252,7 @@ pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx
 
     fn unsetenv(&mut self, name_op: OpTy<'tcx, Tag>) -> InterpResult<'tcx, i32> {
         let this = self.eval_context_mut();
-        let target_os = this.tcx.sess.target.target.target_os.as_str();
+        let target_os = &this.tcx.sess.target.target.target_os;
         assert!(target_os == "linux" || target_os == "macos", "`unsetenv` is only available for the UNIX target family");
 
         let name_ptr = this.read_scalar(name_op)?.not_undef()?;