Bug 1580518: Don't explicitly depend on target-lexicon for Cranelift's build; r=nbp

This means that every update of target-lexicon in Cranelift won't require
Spidermonkey developers to bump the version number of target-lexicon in
Baldrdash.

Differential Revision: https://phabricator.services.mozilla.com/D45549

--HG--
extra : moz-landing-system : lando

Cargo.lock

@@ -203,7 +203,6 @@ dependencies = [
  "env_logger 0.5.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "log 0.4.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "smallvec 0.6.10 (registry+https://github.com/rust-lang/crates.io-index)",
- "target-lexicon 0.8.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [[package]]

js/src/wasm/cranelift/Cargo.toml

@@ -18,7 +18,6 @@ name = "baldrdash"
 # Cranelift source.
 cranelift-codegen = { version = "0.42", default-features = false }
 cranelift-wasm = "0.42"
-target-lexicon = "0.8.0"
 log = { version = "0.4.6", default-features = false, features = ["release_max_level_info"] }
 env_logger = "0.5.6"
 smallvec = { version = "0.6.6" }

js/src/wasm/cranelift/src/isa.rs

@@ -157,9 +157,7 @@ fn make_shared_flags(
 
 #[cfg(feature = "cranelift_x86")]
 fn make_isa_specific(env: &StaticEnvironment) -> DashResult<isa::Builder> {
-    use std::str::FromStr; // for the triple! macro below.
-
-    let mut ib = isa::lookup(triple!("x86_64-unknown-unknown")).map_err(BasicError::from)?;
+    let mut ib = isa::lookup_by_name("x86_64-unknown-unknown").map_err(BasicError::from)?;
 
     if !env.hasSse2 {
         return Err("SSE2 is mandatory for Baldrdash!".into());

js/src/wasm/cranelift/src/lib.rs

@@ -13,10 +13,6 @@
  * limitations under the License.
  */
 
-#[cfg(feature = "cranelift_x86")]
-#[macro_use]
-extern crate target_lexicon;
-
 #[macro_use]
 extern crate log;