compiler: reuse stowed Target::abi_map

We preserve `AbiMap::from_target` for now as other PRs in flight use it.
We will remove it from public API when it isn't a gratuitous conflict.

Author: workingjubilee

compiler/rustc_hir_analysis/src/check/check.rs

@@ -25,7 +25,7 @@ use rustc_middle::ty::{
     TypeVisitable, TypeVisitableExt, fold_regions,
 };
 use rustc_session::lint::builtin::UNINHABITED_STATIC;
-use rustc_target::spec::{AbiMap, AbiMapping};
+use rustc_target::spec::AbiMapping;
 use rustc_trait_selection::error_reporting::InferCtxtErrorExt;
 use rustc_trait_selection::error_reporting::traits::on_unimplemented::OnUnimplementedDirective;
 use rustc_trait_selection::traits;
@@ -55,7 +55,7 @@ pub fn check_abi(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: ExternAbi
     // FIXME: this should be checked earlier, e.g. in `rustc_ast_lowering`, to fix
     // things like #86232.
 
-    match AbiMap::from_target(&tcx.sess.target).canonize_abi(abi, false) {
+    match tcx.sess.target.abi_map().canonize_abi(abi, false) {
         AbiMapping::Direct(..) => (),
         AbiMapping::Invalid => {
             let mut err = struct_span_code_err!(
@@ -79,7 +79,7 @@ pub fn check_abi(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: ExternAbi
 pub fn check_abi_fn_ptr(tcx: TyCtxt<'_>, hir_id: hir::HirId, span: Span, abi: ExternAbi) {
     // This is always an FCW, even for `AbiMapping::Invalid`, since we started linting later than
     // in `check_abi` above.
-    match AbiMap::from_target(&tcx.sess.target).canonize_abi(abi, false) {
+    match tcx.sess.target.abi_map().canonize_abi(abi, false) {
         AbiMapping::Direct(..) => (),
         // This is not a redundant match arm: these ABIs started linting after introducing
         // UNSUPPORTED_FN_PTR_CALLING_CONVENTIONS already existed and we want to

compiler/rustc_ty_utils/src/abi.rs

@@ -14,7 +14,7 @@ use rustc_session::config::OptLevel;
 use rustc_span::DUMMY_SP;
 use rustc_span::def_id::DefId;
 use rustc_target::callconv::{
-    AbiMap, ArgAbi, ArgAttribute, ArgAttributes, ArgExtension, FnAbi, PassMode,
+    ArgAbi, ArgAttribute, ArgAttributes, ArgExtension, FnAbi, PassMode,
 };
 use tracing::debug;
 
@@ -481,8 +481,7 @@ fn fn_abi_new_uncached<'tcx>(
     };
     let sig = tcx.normalize_erasing_regions(cx.typing_env, sig);
 
-    let abi_map = AbiMap::from_target(&tcx.sess.target);
-    let conv = abi_map.canonize_abi(sig.abi, sig.c_variadic).unwrap();
+    let conv = tcx.sess.target.abi_map().canonize_abi(sig.abi, sig.c_variadic).unwrap();
 
     let mut inputs = sig.inputs();
     let extra_args = if sig.abi == ExternAbi::RustCall {