rustc: Remove sret attributes from functions

Something about the way we're using it is causing incorrect code generation.

Closes #1343

Author: brson

src/comp/middle/trans.rs

@@ -4475,11 +4475,6 @@ fn create_llargs_for_fn_args(cx: @fn_ctxt, ty_self: self_arg,
 
 fn copy_args_to_allocas(fcx: @fn_ctxt, bcx: @block_ctxt, args: [ast::arg],
                         arg_tys: [ty::arg]) -> @block_ctxt {
-    if fcx_ccx(fcx).sess.get_opts().extra_debuginfo {
-        llvm::LLVMAddAttribute(llvm::LLVMGetFirstParam(fcx.llfn),
-                               lib::llvm::LLVMStructRetAttribute as
-                                   lib::llvm::llvm::Attribute);
-    }
     let arg_n: uint = 0u, bcx = bcx;
     for arg in arg_tys {
         let id = args[arg_n].id;

src/comp/middle/trans_build.rs

@@ -93,14 +93,9 @@ fn Invoke(cx: @block_ctxt, Fn: ValueRef, Args: [ValueRef],
     assert (!cx.terminated);
     cx.terminated = true;
     unsafe {
-        let instr = llvm::LLVMBuildInvoke(B(cx), Fn, vec::to_ptr(Args),
-                                          vec::len(Args), Then, Catch,
-                                          noname());
-        if bcx_ccx(cx).sess.get_opts().debuginfo {
-            llvm::LLVMAddInstrAttribute(instr, 1u,
-                                        lib::llvm::LLVMStructRetAttribute as
-                                            lib::llvm::llvm::Attribute);
-        }
+        llvm::LLVMBuildInvoke(B(cx), Fn, vec::to_ptr(Args),
+                              vec::len(Args), Then, Catch,
+                              noname());
     }
 }