Auto merge of #32803 - eddyb:mir-debuginfo, r=nikomatsakis

Initial implementation of debuginfo in MIR trans.

Progress is made towards #31005, but several issues remain, such as #32790.

src/librustc/mir/repr.rs

@@ -698,6 +698,7 @@ impl ScopeId {
 
 #[derive(Clone, Debug, RustcEncodable, RustcDecodable)]
 pub struct ScopeData {
+    pub span: Span,
     pub parent_scope: Option<ScopeId>,
 }
 

src/librustc/mir/visit.rs

@@ -298,9 +298,11 @@ macro_rules! make_mir_visitor {
             fn super_scope_data(&mut self,
                                 scope_data: & $($mutability)* ScopeData) {
                 let ScopeData {
+                    ref $($mutability)* span,
                     ref $($mutability)* parent_scope,
                 } = *scope_data;
 
+                self.visit_span(span);
                 if let Some(ref $($mutability)* parent_scope) = *parent_scope {
                     self.visit_scope_id(parent_scope);
                 }