Rename 'an block' to 'a block'

Missed this in the automatic rename of 'Ebb' to 'Block'.

cranelift/codegen/src/legalizer/heap.rs

@@ -121,7 +121,7 @@ fn static_addr(
         pos.func.dfg.replace(inst).iconst(addr_ty, 0);
 
         // Split Block, as the trap is a terminator instruction.
-        let curr_block = pos.current_block().expect("Cursor is not in an block");
+        let curr_block = pos.current_block().expect("Cursor is not in a block");
         let new_block = pos.func.dfg.make_block();
         pos.insert_block(new_block);
         cfg.recompute_block(pos.func, curr_block);

cranelift/codegen/src/legalizer/split.rs

@@ -95,7 +95,7 @@ pub fn vsplit(
     split_any(func, cfg, pos, srcloc, value, Opcode::Vconcat)
 }
 
-/// After splitting an block argument, we need to go back and fix up all of the predecessor
+/// After splitting a block argument, we need to go back and fix up all of the predecessor
 /// instructions. This is potentially a recursive operation, but we don't implement it recursively
 /// since that could use up too muck stack.
 ///
@@ -260,7 +260,7 @@ fn split_value(
             }
         }
         ValueDef::Param(block, num) => {
-            // This is an block parameter.
+            // This is a block parameter.
             // We can split the parameter value unless this is the entry block.
             if pos.func.layout.entry_block() != Some(block) {
                 reuse = Some(split_block_param(pos, block, num, value, concat, repairs));