Change the target data layout to specify more values

This does not actually alter the previously specified important parts, but apparently `rustc` cares about more layout components than `cargo-xbuild` ever did. This extends the data layout to be fully specified layout, as given in the error from issue rust-lang#74767

Author: Lokathor

src/librustc_target/spec/thumbv4t_none_eabi.rs

@@ -29,7 +29,7 @@ pub fn target() -> TargetResult {
          * native integers are 32-bit
          * All other elements are default
          */
-        data_layout: "e-S64-p:32:32-i64:64-m:e-n32".to_string(),
+        data_layout: "e-m:e-p:32:32-Fi8-i64:64-v128:64:128-a:0:32-n32-S64".to_string(),
         linker_flavor: LinkerFlavor::Ld,
         options: TargetOptions {
             linker: Some("arm-none-eabi-ld".to_string()),