Whitelist wasm32 simd128 target feature

src/librustc_codegen_llvm/llvm_util.rs

@@ -169,6 +169,10 @@ const MIPS_WHITELIST: &[(&str, Option<&str>)] = &[
     ("msa", Some("mips_target_feature")),
 ];
 
+const WASM_WHITELIST: &[(&str, Option<&str>)] = &[
+    ("simd128", Some("wasm_target_feature")),
+];
+
 /// When rustdoc is running, provide a list of all known features so that all their respective
 /// primtives may be documented.
 ///
@@ -181,6 +185,7 @@ pub fn all_known_features() -> impl Iterator<Item=(&'static str, Option<&'static
         .chain(HEXAGON_WHITELIST.iter().cloned())
         .chain(POWERPC_WHITELIST.iter().cloned())
         .chain(MIPS_WHITELIST.iter().cloned())
+        .chain(WASM_WHITELIST.iter().cloned())
 }
 
 pub fn to_llvm_feature<'a>(sess: &Session, s: &'a str) -> &'a str {
@@ -228,6 +233,7 @@ pub fn target_feature_whitelist(sess: &Session)
         "hexagon" => HEXAGON_WHITELIST,
         "mips" | "mips64" => MIPS_WHITELIST,
         "powerpc" | "powerpc64" => POWERPC_WHITELIST,
+        "wasm32" => WASM_WHITELIST,
         _ => &[],
     }
 }

src/libsyntax/feature_gate.rs

@@ -446,6 +446,7 @@ declare_features! (
     (active, mmx_target_feature, "1.27.0", Some(44839), None),
     (active, sse4a_target_feature, "1.27.0", Some(44839), None),
     (active, tbm_target_feature, "1.27.0", Some(44839), None),
+    (active, wasm_target_feature, "1.30.0", Some(44839), None),
 
     // Allows macro invocations of the form `#[foo::bar]`
     (active, proc_macro_path_invoc, "1.27.0", Some(38356), None),

src/test/ui/target-feature-gate.rs

@@ -23,6 +23,7 @@
 // gate-test-hexagon_target_feature
 // gate-test-mips_target_feature
 // gate-test-mmx_target_feature
+// gate-test-wasm_target_feature
 // min-llvm-version 6.0
 
 #[target_feature(enable = "avx512bw")]

src/test/ui/target-feature-gate.stderr

@@ -1,5 +1,5 @@
 error[E0658]: the target feature `avx512bw` is currently unstable (see issue #44839)
-  --> $DIR/target-feature-gate.rs:28:18
+  --> $DIR/target-feature-gate.rs:29:18
    |
 LL | #[target_feature(enable = "avx512bw")]
    |                  ^^^^^^^^^^^^^^^^^^^