Fix SPARC64 int-to-TFmode conversions

[David Miller]

From: "Joseph S. Myers" <joseph@codesourcery.com>
Date: Wed, 13 Aug 2008 19:02:53 +0000 (UTC)

> Tests of conversion of integers to TFmode were failing for SPARC64,
> because these were implemented by passing an SImode value to a
> libcall, and the libcall expansion could not know whether that value
> needed to be sign or zero extended to go in a 64-bit argument
> register.  This patch adds the necessary explicit extensions.  (The
> problem case I reduced a test to was a signed value being wrongly
> zero-extended, but it seems cleanest to insert the extensions for both
> signed and unsigned values, whther or not required in both cases.)
> 
> Tested with no regressions with cross to sparc64-linux-gnu, where it
> fixes the following test failures.  OK to commit?

This looks fine to me.