Small doc fix.

Hi,

The LLVM Assembly Language Reference [1] incorrectly states that the
prefix used for dll{import,export} is _imp__; it is actually __imp_.
The attached patch fixes this.

Thanks & Regards,
-Mahadevan.

[1] file:///home/mdevan/llvm/docs/LangRef.html#linkage

doc-dllimport-prefix.patch (1.07 KB)

Applied, thanks!

Dan