Remove (lots of) dead code

Found with https://github.com/est31/warnalyzer.

Dubious changes:
- Is anyone else using rustc_apfloat? I feel weird completely deleting
  x87 support.
- Maybe some of the dead code in rustc_data_structures, in case someone
  wants to use it in the future?
- Don't change rustc_serialize

  I plan to scrap most of the json module in the near future (see
  https://github.com/rust-lang/compiler-team/issues/418) and fixing the
  tests needed more work than I expected.

TODO: check if any of the comments on the deleted code should be kept.

1 files changed, 0 insertions, 4 deletions

diff --git a/compiler/rustc_ast_pretty/src/pprust/state.rs b/compiler/rustc_ast_pretty/src/pprust/state.rs
index 84f8ce5706a..627c0584b61 100644
--- a/compiler/rustc_ast_pretty/src/pprust/state.rs
+++ b/compiler/rustc_ast_pretty/src/pprust/state.rs
@@ -2292,10 +2292,6 @@ impl<'a> State<'a> {
         }
     }
 
-    pub fn print_usize(&mut self, i: usize) {
-        self.s.word(i.to_string())
-    }
-
     crate fn print_name(&mut self, name: Symbol) {
         self.s.word(name.to_string());
         self.ann.post(self, AnnNode::Name(&name))