Auto merge of #58408 - alexcrichton:update-llvm, r=michaelwoerister

rustc: Update LLVM, remove dead wasm code

This commit updates the LLVM branch to the rebased version of the
upstream release/8.x branch. This includes a wasm patch which means that
the `rewrite_imports` pass in rustc is no longer needed (yay!) and we
can instead rely on `wasm-import-module`, an attribute we're already
emitting, to take care of all the work.

2 files changed, 1 insertions, 24 deletions

diff --git a/src/librustc_codegen_ssa/base.rs b/src/librustc_codegen_ssa/base.rs
index fad41a11a82..39ce15e4772 100644
--- a/src/librustc_codegen_ssa/base.rs
+++ b/src/librustc_codegen_ssa/base.rs
@@ -16,7 +16,7 @@
 use crate::{ModuleCodegen, ModuleKind, CachedModuleCodegen};
 
 use rustc::dep_graph::cgu_reuse_tracker::CguReuse;
-use rustc::hir::def_id::{CrateNum, DefId, LOCAL_CRATE};
+use rustc::hir::def_id::{DefId, LOCAL_CRATE};
 use rustc::middle::lang_items::StartFnLangItem;
 use rustc::middle::weak_lang_items;
 use rustc::mir::mono::{Stats, CodegenUnitNameBuilder};
@@ -816,21 +816,11 @@ impl CrateInfo {
             used_crates_dynamic: cstore::used_crates(tcx, LinkagePreference::RequireDynamic),
             used_crates_static: cstore::used_crates(tcx, LinkagePreference::RequireStatic),
             used_crate_source: Default::default(),
-            wasm_imports: Default::default(),
             lang_item_to_crate: Default::default(),
             missing_lang_items: Default::default(),
         };
         let lang_items = tcx.lang_items();
 
-        let load_wasm_items = tcx.sess.crate_types.borrow()
-            .iter()
-            .any(|c| *c != config::CrateType::Rlib) &&
-            tcx.sess.opts.target_triple.triple() == "wasm32-unknown-unknown";
-
-        if load_wasm_items {
-            info.load_wasm_imports(tcx, LOCAL_CRATE);
-        }
-
         let crates = tcx.crates();
 
         let n_crates = crates.len();
@@ -858,9 +848,6 @@ impl CrateInfo {
             if tcx.is_no_builtins(cnum) {
                 info.is_no_builtins.insert(cnum);
             }
-            if load_wasm_items {
-                info.load_wasm_imports(tcx, cnum);
-            }
             let missing = tcx.missing_lang_items(cnum);
             for &item in missing.iter() {
                 if let Ok(id) = lang_items.require(item) {
@@ -879,15 +866,6 @@ impl CrateInfo {
 
         return info
     }
-
-    fn load_wasm_imports(&mut self, tcx: TyCtxt<'_, '_, '_>, cnum: CrateNum) {
-        self.wasm_imports.extend(tcx.wasm_import_module_map(cnum).iter().map(|(&id, module)| {
-            let instance = Instance::mono(tcx, id);
-            let import_name = tcx.symbol_name(instance);
-
-            (import_name.to_string(), module.clone())
-        }));
-    }
 }
 
 fn is_codegened_item(tcx: TyCtxt<'_, '_, '_>, id: DefId) -> bool {
diff --git a/src/librustc_codegen_ssa/lib.rs b/src/librustc_codegen_ssa/lib.rs
index 92fa2766f87..f38b22aa041 100644
--- a/src/librustc_codegen_ssa/lib.rs
+++ b/src/librustc_codegen_ssa/lib.rs
@@ -138,7 +138,6 @@ pub struct CrateInfo {
     pub used_crate_source: FxHashMap<CrateNum, Lrc<CrateSource>>,
     pub used_crates_static: Vec<(CrateNum, LibSource)>,
     pub used_crates_dynamic: Vec<(CrateNum, LibSource)>,
-    pub wasm_imports: FxHashMap<String, String>,
     pub lang_item_to_crate: FxHashMap<LangItem, CrateNum>,
     pub missing_lang_items: FxHashMap<CrateNum, Vec<LangItem>>,
 }