rollup merge of #21845: Potpourri/import-syntax

syntax like `use foo::bar::;` and `use foo:: as bar;` should be rejected, see issue #21629

src/libsyntax/parse/parser.rs

@@ -5917,9 +5917,9 @@ impl<'a> Parser<'a> {
                 self.bump();
 
                 match self.token {
-                  token::Ident(i, _) => {
-                    self.bump();
-                    path.push(i);
+                  token::Ident(..) => {
+                    let ident = self.parse_ident();
+                    path.push(ident);
                   }
 
                   // foo::bar::{a,b,c}
@@ -5959,6 +5959,11 @@ impl<'a> Parser<'a> {
                     return P(spanned(lo, self.span.hi, ViewPathGlob(path)));
                   }
 
+                  // fall-through for case foo::bar::;
+                  token::Semi => {
+                    self.span_err(self.span, "expected identifier or `{` or `*`, found `;`");
+                  }
+
                   _ => break
                 }
             }