bootstrap: Delete handling of RUSTC_METADATA_SUFFIX

This is already handled by `__CARGO_DEFAULT_LIB_METADATA` so there's no
need to doubly do it.

Author: alexcrichton

src/bootstrap/bin/rustc.rs

@@ -24,23 +24,7 @@ use std::str::FromStr;
 use std::time::Instant;
 
 fn main() {
-    let mut args = env::args_os().skip(1).collect::<Vec<_>>();
-
-    // Append metadata suffix for internal crates. See the corresponding entry
-    // in bootstrap/lib.rs for details.
-    if let Ok(s) = env::var("RUSTC_METADATA_SUFFIX") {
-        for i in 1..args.len() {
-            // Dirty code for borrowing issues
-            let mut new = None;
-            if let Some(current_as_str) = args[i].to_str() {
-                if (&*args[i - 1] == "-C" && current_as_str.starts_with("metadata")) ||
-                    current_as_str.starts_with("-Cmetadata") {
-                    new = Some(format!("{}-{}", current_as_str, s));
-                }
-            }
-            if let Some(new) = new { args[i] = new.into(); }
-        }
-    }
+    let args = env::args_os().skip(1).collect::<Vec<_>>();
 
     // Detect whether or not we're a build script depending on whether --target
     // is passed (a bit janky...)

src/bootstrap/builder.rs

@@ -939,24 +939,6 @@ impl<'a> Builder<'a> {
 
         if !mode.is_tool() {
             cargo.env("RUSTC_FORCE_UNSTABLE", "1");
-
-            // Currently the compiler depends on crates from crates.io, and
-            // then other crates can depend on the compiler (e.g., proc-macro
-            // crates). Let's say, for example that rustc itself depends on the
-            // bitflags crate. If an external crate then depends on the
-            // bitflags crate as well, we need to make sure they don't
-            // conflict, even if they pick the same version of bitflags. We'll
-            // want to make sure that e.g., a plugin and rustc each get their
-            // own copy of bitflags.
-
-            // Cargo ensures that this works in general through the -C metadata
-            // flag. This flag will frob the symbols in the binary to make sure
-            // they're different, even though the source code is the exact
-            // same. To solve this problem for the compiler we extend Cargo's
-            // already-passed -C metadata flag with our own. Our rustc.rs
-            // wrapper around the actual rustc will detect -C metadata being
-            // passed and frob it with this extra string we're passing in.
-            cargo.env("RUSTC_METADATA_SUFFIX", "rustc");
         }
 
         if let Some(x) = self.crt_static(target) {