assertion failure w/(invalid?) inline assembly

[androm3da]

This example fails w/an assertion error:

http://is.gd/GsxTMy

rustc: /home/rustbuild/src/rust-buildbot/slave/nightly-dist-rustc-linux/build/src/llvm/include/llvm/CodeGen/FunctionLoweringInfo.h:169: unsigned int llvm::FunctionLoweringInfo::InitializeRegForValue(const llvm::Value*): Assertion `R == 0 && "Already initialized this value register!"' failed.
Aborted (core dumped)

Source:

#![feature(asm)]

#[cfg(any(target_arch = "x86", target_arch = "x86_64"))]
fn get_timer() -> i32 {
    let tsc: i32;
    unsafe {
        asm!("nop": "=a"(tsc));
    }
    tsc
}

fn main() {
    println!("Val: {}", get_timer());
}

Correcting the "=a"(tsc) to be "=A"(tsc) makes the assertion error go away.

[19h]

This code does not compile in the latest nightly, although the correct variant does. I'd consider this bug fixed.