Revert "Fix rebase fallout"

This reverts commit 5685e4dd90.

Cargo.lock

@@ -4143,7 +4143,6 @@ dependencies = [
  "rustc_lexer",
  "rustc_session",
  "rustc_span",
- "smallvec 1.4.0",
  "unicode-normalization",
 ]
 

src/librustc_ast/tokenstream.rs

@@ -21,6 +21,8 @@ use rustc_macros::HashStable_Generic;
 use rustc_span::{Span, DUMMY_SP};
 use smallvec::{smallvec, SmallVec};
 
+use log::debug;
+
 use std::{iter, mem};
 
 /// When the main rust parser encounters a syntax-extension invocation, it

src/librustc_parse/Cargo.toml

@@ -12,7 +12,6 @@ doctest = false
 [dependencies]
 bitflags = "1.0"
 log = "0.4"
-smallvec = { version = "1.0", features = ["union", "may_dangle"] }
 rustc_ast_pretty = { path = "../librustc_ast_pretty" }
 rustc_data_structures = { path = "../librustc_data_structures" }
 rustc_feature = { path = "../librustc_feature" }

src/librustc_parse/lib.rs

@@ -14,9 +14,7 @@ use rustc_data_structures::sync::Lrc;
 use rustc_errors::{Diagnostic, FatalError, Level, PResult};
 use rustc_session::parse::ParseSess;
 use rustc_span::symbol::kw;
-use rustc_span::{FileName, SourceFile, Span, DUMMY_SP};
+use rustc_span::{FileName, SourceFile, Span};
-
-use smallvec::SmallVec;
 
 use std::mem;
 use std::path::Path;