fix: alloc_instead_of_core FP when alloc is an alias

Author: profetia

clippy_lints/src/std_instead_of_core.rs

@@ -127,6 +127,13 @@ impl<'tcx> LateLintPass<'tcx> for StdReexports {
             && !matches!(def_kind, DefKind::Macro(_))
             && let Some(last_segment) = path.segments.last()
         {
+            if let Res::Def(DefKind::Mod, crate_def_id) = first_segment.res
+                && let crate_name = cx.tcx.crate_name(crate_def_id.krate)
+                && crate_name != first_segment.ident.name
+            {
+                return;
+            }
+
             let (lint, used_mod, replace_with) = match first_segment.ident.name {
                 sym::std => match cx.tcx.crate_name(def_id.krate) {
                     sym::core => (STD_INSTEAD_OF_CORE, "std", "core"),

tests/ui/std_instead_of_core.fixed

@@ -89,3 +89,9 @@ fn msrv_1_76(_: std::net::IpAddr) {}
 #[clippy::msrv = "1.77"]
 fn msrv_1_77(_: core::net::IpAddr) {}
 //~^ std_instead_of_core
+
+fn issue15579() {
+    use std::alloc;
+
+    let layout = alloc::Layout::new::<u8>();
+}

tests/ui/std_instead_of_core.rs

@@ -89,3 +89,9 @@ fn msrv_1_76(_: std::net::IpAddr) {}
 #[clippy::msrv = "1.77"]
 fn msrv_1_77(_: std::net::IpAddr) {}
 //~^ std_instead_of_core
+
+fn issue15579() {
+    use std::alloc;
+
+    let layout = alloc::Layout::new::<u8>();
+}