Remove warnings/errors from compiler when using typeck_body in rustdoc span map builder

compiler/rustc_errors/src/lib.rs

@@ -342,6 +342,9 @@ struct HandlerInner {
     deduplicated_warn_count: usize,
 
     future_breakage_diagnostics: Vec<Diagnostic>,
+
+    /// If set to `true`, no warning or error will be emitted.
+    quiet: bool,
 }
 
 /// A key denoting where from a diagnostic was stashed.
@@ -456,10 +459,19 @@ impl Handler {
                 emitted_diagnostics: Default::default(),
                 stashed_diagnostics: Default::default(),
                 future_breakage_diagnostics: Vec::new(),
+                quiet: false,
             }),
         }
     }
 
+    pub fn with_disabled_diagnostic<T, F: FnOnce() -> T>(&self, f: F) -> T {
+        let prev = self.inner.borrow_mut().quiet;
+        self.inner.borrow_mut().quiet = true;
+        let ret = f();
+        self.inner.borrow_mut().quiet = prev;
+        ret
+    }
+
     // This is here to not allow mutation of flags;
     // as of this writing it's only used in tests in librustc_middle.
     pub fn can_emit_warnings(&self) -> bool {
@@ -818,7 +830,7 @@ impl HandlerInner {
     }
 
     fn emit_diagnostic(&mut self, diagnostic: &Diagnostic) {
-        if diagnostic.cancelled() {
+        if diagnostic.cancelled() || self.quiet {
             return;
         }
 
@@ -1035,6 +1047,9 @@ impl HandlerInner {
     }
 
     fn delay_as_bug(&mut self, diagnostic: Diagnostic) {
+        if self.quiet {
+            return;
+        }
         if self.flags.report_delayed_bugs {
             self.emit_diagnostic(&diagnostic);
         }