Remove support for datalayout upgrade

Only keep the downgrade code

src/librustc_codegen_llvm/context.rs

@@ -147,18 +147,6 @@ fn strip_x86_address_spaces(data_layout: String) -> String {
     data_layout.replace("-p270:32:32-p271:32:32-p272:64:64-", "-")
 }
 
-fn add_x86_address_spaces(mut data_layout: String) -> String {
-    let address_spaces = "-p270:32:32-p271:32:32-p272:64:64";
-    if !data_layout.contains(address_spaces) && data_layout.starts_with("e-m:") {
-        let mut insert_pos = "e-m:?".len();
-        if data_layout[insert_pos..].starts_with("-p:32:32") {
-            insert_pos += "-p:32:32".len();
-        }
-        data_layout.insert_str(insert_pos, address_spaces);
-    }
-    data_layout
-}
-
 pub unsafe fn create_module(
     tcx: TyCtxt<'_>,
     llcx: &'ll llvm::Context,
@@ -172,11 +160,9 @@ pub unsafe fn create_module(
     if llvm_util::get_major_version() < 9 {
         target_data_layout = strip_function_ptr_alignment(target_data_layout);
     }
-    if sess.target.target.arch == "x86" || sess.target.target.arch == "x86_64" {
-        if llvm_util::get_major_version() < 10 {
+    if llvm_util::get_major_version() < 10 {
+        if sess.target.target.arch == "x86" || sess.target.target.arch == "x86_64" {
             target_data_layout = strip_x86_address_spaces(target_data_layout);
-        } else {
-            target_data_layout = add_x86_address_spaces(target_data_layout);
         }
     }