Use SHA256 by default when targeting MSVC

Author: sivadeilra

compiler/rustc_session/src/session.rs

@@ -1420,7 +1420,7 @@ pub fn build_session(
     let loader = file_loader.unwrap_or_else(|| Box::new(RealFileLoader));
     let hash_kind = sopts.unstable_opts.src_hash_algorithm.unwrap_or_else(|| {
         if target_cfg.is_like_msvc {
-            SourceFileHashAlgorithm::Sha1
+            SourceFileHashAlgorithm::Sha256
         } else {
             SourceFileHashAlgorithm::Md5
         }