Fixed spurious cannot borrow immutable item error with a closure.

diff --git a/src/librustc_mir/build/mod.rs b/src/librustc_mir/build/mod.rs
index d8011e151d8e380834b4f4ae39ff9f4d751e9721..76b20bca7bb5612022478cb52ec993635b0d3de9 100644 (file)
--- a/src/librustc_mir/build/mod.rs
+++ b/src/librustc_mir/build/mod.rs
@@ -581,7 +581,7 @@ fn args_and_body(&mut self,
             }
 
             self.local_decls.push(LocalDecl {
-                mutability: Mutability::Not,
+                mutability: Mutability::Mut,
                 ty,
                 source_info: SourceInfo {
                     scope: ARGUMENT_VISIBILITY_SCOPE,