Rollup merge of #144143 - Gelbpunkt:target-features-crt-static, r=RalfJung

Fix `-Ctarget-feature`s getting ignored after `crt-static`

The current behaviour introduced by commit a50a3b8e31 would discard any target features specified after `crt-static` (the only member of `RUSTC_SPECIFIC_FEATURES`). This is because it returned instead of continuing processing the next feature.

I wasn't entirely sure how the regression test should look like, but this one should do. If anyone has some suggestions, I'm happy to learn, it's my first test :)

I've confirmed that the test fails without the fix on `powerpc64le-unknown-linux-musl` and `x86_64-unknown-linux-gnu`.

cc ``@RalfJung``

compiler/rustc_codegen_ssa/src/target_features.rs

@@ -149,14 +149,14 @@ fn parse_rust_feature_flag<'a>(
         if let Some(base_feature) = feature.strip_prefix('+') {
             // Skip features that are not target features, but rustc features.
             if RUSTC_SPECIFIC_FEATURES.contains(&base_feature) {
-                return;
+                continue;
             }
 
             callback(base_feature, sess.target.implied_target_features(base_feature), true)
         } else if let Some(base_feature) = feature.strip_prefix('-') {
             // Skip features that are not target features, but rustc features.
             if RUSTC_SPECIFIC_FEATURES.contains(&base_feature) {
-                return;
+                continue;
             }
 
             // If `f1` implies `f2`, then `!f2` implies `!f1` -- this is standard logical

tests/ui/cfg/crt-static-with-target-features-works.rs

@@ -0,0 +1,24 @@
+// Test to ensure that specifying a value for crt-static in target features
+// does not result in skipping the features following it.
+// This is a regression test for #144143
+
+//@ add-core-stubs
+//@ needs-llvm-components: x86
+//@ compile-flags: --target=x86_64-unknown-linux-gnu
+//@ compile-flags: -Ctarget-feature=+crt-static,+avx2
+
+#![crate_type = "rlib"]
+#![feature(no_core, rustc_attrs, lang_items)]
+#![no_core]
+
+extern crate minicore;
+use minicore::*;
+
+#[rustc_builtin_macro]
+macro_rules! compile_error {
+    () => {};
+}
+
+#[cfg(target_feature = "avx2")]
+compile_error!("+avx2");
+//~^ ERROR: +avx2

tests/ui/cfg/crt-static-with-target-features-works.stderr

@@ -0,0 +1,8 @@
+error: +avx2
+  --> $DIR/crt-static-with-target-features-works.rs:23:1
+   |
+LL | compile_error!("+avx2");
+   | ^^^^^^^^^^^^^^^^^^^^^^^
+
+error: aborting due to 1 previous error
+