Rename DiagnosticMessage as DiagMessage.

Author: nnethercote

tests/ui-internal/disallow_span_lint.rs

@@ -5,12 +5,17 @@ extern crate rustc_hir;
 extern crate rustc_lint;
 extern crate rustc_middle;
 
-use rustc_errors::{DiagnosticMessage, MultiSpan};
+use rustc_errors::{DiagMessage, MultiSpan};
 use rustc_hir::hir_id::HirId;
 use rustc_lint::{Lint, LintContext};
 use rustc_middle::ty::TyCtxt;
 
-pub fn a(cx: impl LintContext, lint: &'static Lint, span: impl Into<MultiSpan>, msg: impl Into<DiagnosticMessage>) {
+pub fn a(
+    cx: impl LintContext,
+    lint: &'static Lint,
+    span: impl Into<MultiSpan>,
+    msg: impl Into<DiagMessage>)
+{
     cx.span_lint(lint, span, msg, |_| {});
 }
 
@@ -19,7 +24,7 @@ pub fn b(
     lint: &'static Lint,
     hir_id: HirId,
     span: impl Into<MultiSpan>,
-    msg: impl Into<DiagnosticMessage>,
+    msg: impl Into<DiagMessage>,
 ) {
     tcx.node_span_lint(lint, hir_id, span, msg, |_| {});
 }