Fix no_std detection for target triples

The current check for wether a target is no_std or not is matching for the
string "-none-" in a target triple. This doesn't work for triples that end in
"-none", like "aarch64-unknown-none".

Fix this by matching for "-none" instead.

I checked for all the current target triples containing "none", and this should
not generate any false positives.

This fixes an issue encountered in rust-lang#68334

Author: andre-richter

src/bootstrap/config.rs

@@ -180,7 +180,7 @@ pub struct Target {
 impl Target {
     pub fn from_triple(triple: &str) -> Self {
         let mut target: Self = Default::default();
-        if triple.contains("-none-") || triple.contains("nvptx") {
+        if triple.contains("-none") || triple.contains("nvptx") {
             target.no_std = true;
         }
         target