Make use generated TerminatorKind::Call have call_source Use

Author: spastorino

Diff for: compiler/rustc_middle/src/mir/syntax.rs

@@ -652,6 +652,8 @@ pub enum CallSource {
     /// Other types of desugaring that did not come from the HIR, but we don't care about
     /// for diagnostics (yet).
     Misc,
+    /// Use of value, generating a clone function call
+    Use,
     /// Normal function call, no special source
     Normal,
 }

Diff for: compiler/rustc_mir_build/src/builder/expr/into.rs

@@ -328,7 +328,7 @@ impl<'a, 'tcx> Builder<'a, 'tcx> {
                             destination,
                             target: Some(success),
                             unwind: UnwindAction::Unreachable,
-                            call_source: CallSource::Misc,
+                            call_source: CallSource::Use,
                             fn_span: expr_span,
                         },
                     );