Move "return" basic block after all other function blocks.

Author: vadimcn

src/librustc/lib/llvm.rs

@@ -966,6 +966,12 @@ pub mod llvm {
                                                  -> BasicBlockRef;
         #[fast_ffi]
         pub unsafe fn LLVMDeleteBasicBlock(BB: BasicBlockRef);
+        
+        #[fast_ffi]
+        pub unsafe fn LLVMMoveBasicBlockAfter(BB: BasicBlockRef, MoveAfter: BasicBlockRef);
+        
+        #[fast_ffi]
+        pub unsafe fn LLVMMoveBasicBlockBefore(BB: BasicBlockRef, MoveBefore: BasicBlockRef);
 
         /* Operations on instructions */
         #[fast_ffi]

src/librustc/middle/trans/base.rs

@@ -1907,6 +1907,8 @@ pub fn trans_closure(ccx: @mut CrateContext,
 
     finish(bcx);
     cleanup_and_Br(bcx, bcx_top, fcx.llreturn);
+    
+    unsafe { llvm::LLVMMoveBasicBlockAfter(fcx.llreturn, bcx.llbb); }
 
     // Insert the mandatory first few basic blocks before lltop.
     finish_fn(fcx, lltop);