Add new_regular and new_allocator to ModuleCodegen

compiler/rustc_codegen_llvm/src/back/lto.rs

@@ -306,11 +306,8 @@ fn fat_lto(
             assert!(!serialized_modules.is_empty(), "must have at least one serialized module");
             let (buffer, name) = serialized_modules.remove(0);
             info!("no in-memory regular modules to choose from, parsing {:?}", name);
-            ModuleCodegen {
-                module_llvm: ModuleLlvm::parse(cgcx, &name, buffer.data(), dcx)?,
-                name: name.into_string().unwrap(),
-                kind: ModuleKind::Regular,
-            }
+            let llvm_module = ModuleLlvm::parse(cgcx, &name, buffer.data(), dcx)?;
+            ModuleCodegen::new_regular(name.into_string().unwrap(), llvm_module)
         }
     };
     {
@@ -778,11 +775,7 @@ pub(crate) unsafe fn optimize_thin_module(
     // crates but for locally codegened modules we may be able to reuse
     // that LLVM Context and Module.
     let module_llvm = ModuleLlvm::parse(cgcx, module_name, thin_module.data(), dcx)?;
-    let mut module = ModuleCodegen {
-        module_llvm,
-        name: thin_module.name().to_string(),
-        kind: ModuleKind::Regular,
-    };
+    let mut module = ModuleCodegen::new_regular(thin_module.name(), module_llvm);
     {
         let target = &*module.module_llvm.tm;
         let llmod = module.module_llvm.llmod();