Use EBB layout order almost everywhere.

The ebbs_numerically() function was a workaround for the unimplemented EBB layout
order.

cranelift/src/libcretonne/cfg.rs

@@ -48,11 +48,11 @@ impl ControlFlowGraph {
 
         // Even ebbs without predecessors should show up in the CFG, albeit
         // with no entires.
-        for ebb in func.ebbs_numerically() {
+        for ebb in &func.layout {
             cfg.init_ebb(ebb);
         }
 
-        for ebb in func.ebbs_numerically() {
+        for ebb in &func.layout {
             // Flips to true when a terminating instruction is seen. So that if additional
             // instructions occur an error may be returned.
             for inst in func.layout.ebb_insts(ebb) {
@@ -120,7 +120,7 @@ mod tests {
         let nodes = cfg.iter().collect::<Vec<_>>();
         assert_eq!(nodes.len(), 3);
 
-        let mut fun_ebbs = func.ebbs_numerically();
+        let mut fun_ebbs = func.layout.ebbs();
         for (ebb, predecessors) in nodes {
             assert_eq!(*ebb, fun_ebbs.next().unwrap());
             assert_eq!(predecessors.len(), 0);

cranelift/src/libcretonne/write.rs

@@ -16,7 +16,7 @@ pub fn write_function(w: &mut Write, func: &Function) -> Result {
     try!(write_spec(w, func));
     try!(writeln!(w, " {{"));
     let mut any = try!(write_preamble(w, func));
-    for ebb in func.ebbs_numerically() {
+    for ebb in &func.layout {
         if any {
             try!(writeln!(w, ""));
         }

cranelift/src/libreader/parser.rs

@@ -1116,7 +1116,7 @@ mod tests {
             .unwrap();
         assert_eq!(func.name, "ebbs");
 
-        let mut ebbs = func.ebbs_numerically();
+        let mut ebbs = func.layout.ebbs();
 
         let ebb0 = ebbs.next().unwrap();
         assert_eq!(func.ebb_args(ebb0).next(), None);

cranelift/src/tools/print_cfg.rs

@@ -106,7 +106,7 @@ impl<T: Write> CFGPrinter<T> {
     }
 
     fn ebb_subgraphs(&mut self, func: &Function) {
-        for ebb in func.ebbs_numerically() {
+        for ebb in &func.layout {
             let inst_data = func.layout
                 .ebb_insts(ebb)
                 .filter(|inst| {