Rename bitcode-in-rlib flag to embed-bitcode

This flag changed names in nightly, so let's rename it here in Cargo to
get our CI passing and enable the same wins for avoiding bitcode.

src/cargo/core/compiler/build_context/target_info.rs

@@ -41,7 +41,7 @@ pub struct TargetInfo {
     /// Extra flags to pass to `rustdoc`, see `env_args`.
     pub rustdocflags: Vec<String>,
     /// Remove this when it hits stable (1.44)
-    pub supports_bitcode_in_rlib: Option<bool>,
+    pub supports_embed_bitcode: Option<bool>,
 }
 
 /// Kind of each file generated by a Unit, part of `FileType`.
@@ -111,10 +111,10 @@ impl TargetInfo {
             .args(&rustflags)
             .env_remove("RUSTC_LOG");
 
-        let mut bitcode_in_rlib_test = process.clone();
-        bitcode_in_rlib_test.arg("-Cbitcode-in-rlib");
-        let supports_bitcode_in_rlib = match kind {
-            CompileKind::Host => Some(rustc.cached_output(&bitcode_in_rlib_test).is_ok()),
+        let mut embed_bitcode_test = process.clone();
+        embed_bitcode_test.arg("-Cembed-bitcode");
+        let supports_embed_bitcode = match kind {
+            CompileKind::Host => Some(rustc.cached_output(&embed_bitcode_test).is_ok()),
             _ => None,
         };
 
@@ -202,7 +202,7 @@ impl TargetInfo {
                 "RUSTDOCFLAGS",
             )?,
             cfg,
-            supports_bitcode_in_rlib,
+            supports_embed_bitcode,
         })
     }
 

src/cargo/core/compiler/mod.rs

@@ -815,10 +815,10 @@ fn build_base_args(
                 .bcx
                 .target_data
                 .info(CompileKind::Host)
-                .supports_bitcode_in_rlib
+                .supports_embed_bitcode
                 .unwrap()
             {
-                cmd.arg("-Cbitcode-in-rlib=no");
+                cmd.arg("-Cembed-bitcode=no");
             }
         }
     }