Rename CodegenUnit::work_product to previous_work_product

It returns the previous work product or panics if there is none. This rename
makes the purpose of this method clearer.

Author: bjorn3

compiler/rustc_codegen_cranelift/src/driver/aot.rs

@@ -85,7 +85,7 @@ fn reuse_workproduct_for_cgu(
     work_products: &mut FxHashMap<WorkProductId, WorkProduct>,
 ) -> CompiledModule {
     let mut object = None;
-    let work_product = cgu.work_product(tcx);
+    let work_product = cgu.previous_work_product(tcx);
     if let Some(saved_file) = &work_product.saved_file {
         let obj_out =
             tcx.output_filenames(()).temp_path(OutputType::Object, Some(cgu.name().as_str()));

compiler/rustc_codegen_ssa/src/base.rs

@@ -716,7 +716,7 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
                     &ongoing_codegen.coordinator_send,
                     CachedModuleCodegen {
                         name: cgu.name().to_string(),
-                        source: cgu.work_product(tcx),
+                        source: cgu.previous_work_product(tcx),
                     },
                 );
                 true
@@ -727,7 +727,7 @@ pub fn codegen_crate<B: ExtraBackendMethods>(
                     &ongoing_codegen.coordinator_send,
                     CachedModuleCodegen {
                         name: cgu.name().to_string(),
-                        source: cgu.work_product(tcx),
+                        source: cgu.previous_work_product(tcx),
                     },
                 );
                 true

compiler/rustc_middle/src/mir/mono.rs

@@ -336,7 +336,7 @@ impl<'tcx> CodegenUnit<'tcx> {
         WorkProductId::from_cgu_name(self.name().as_str())
     }
 
-    pub fn work_product(&self, tcx: TyCtxt<'_>) -> WorkProduct {
+    pub fn previous_work_product(&self, tcx: TyCtxt<'_>) -> WorkProduct {
         let work_product_id = self.work_product_id();
         tcx.dep_graph
             .previous_work_product(&work_product_id)