Re-enable a bunch of fixed rustc tests

Author: bjorn3

scripts/test_rustc_tests.sh

@@ -44,10 +44,8 @@ rm tests/ui/proc-macro/allowed-signatures.rs
 rm tests/ui/proc-macro/no-mangle-in-proc-macro-issue-111888.rs
 
 # vendor intrinsics
-rm tests/ui/sse2.rs # cpuid not supported, so sse2 not detected
+rm tests/ui/sse2.rs # CodegenBackend::target_features not yet implemented
 rm tests/ui/simd/array-type.rs # "Index argument for `simd_insert` is not a constant"
-rm tests/ui/simd/intrinsic/generic-bswap-byte.rs # simd_bswap not yet implemented
-rm tests/ui/simd/intrinsic/generic-arithmetic-pass.rs # many missing simd intrinsics
 
 # exotic linkages
 rm tests/ui/issues/issue-33992.rs # unsupported linkages

src/lib.rs

@@ -186,7 +186,7 @@ impl CodegenBackend for CraneliftCodegenBackend {
     }
 
     fn target_features(&self, _sess: &Session, _allow_unstable: bool) -> Vec<rustc_span::Symbol> {
-        vec![]
+        vec![] // FIXME necessary for #[cfg(target_feature]
     }
 
     fn print_version(&self) {