Work around GCC 4.7.0 bug on ia64 and improve the GMP-ECM spkg

Imported from <a href="http://trac.sagemath.org/sage_trac/ticket/12830">trac #12830</a>.

Diff between my p6 and p7 spkgs.  For reference / review only.

Reported by: leif

Component: packages

CC: hedtke,, justin

Report Upstream: N/A

Authors: Leif Leonhardy

Dependencies: 

Work issues: 

Reviewers: Jeroen Demeyer

Merged in: sage-5.0.rc0

Attachments: <ol><li><a href="http://trac.sagemath.org/sage_trac/attachment/ticket/12830/ecm-6.3.p4-p5.diff">ecm-6.3.p4-p5.diff: Diff between the previous spkg in Sage and my new p5 spkg.  For reference / review only.</a> by leif at 20120411T11:25:28</li><li><a href="http://trac.sagemath.org/sage_trac/attachment/ticket/12830/ecm-6.3.p5-p6.diff">ecm-6.3.p5-p6.diff: Diff between my p5 and p6 spkgs.  For reference / review only.</a> by leif at 20120416T22:36:03</li><li><a href="http://trac.sagemath.org/sage_trac/attachment/ticket/12830/ecm-6.3.p4-p6.diff">ecm-6.3.p4-p6.diff: Diff between the previous spkg in Sage and my new p6 spkg.  For reference / review only.</a> by leif at 20120416T22:36:51</li><li><a href="http://trac.sagemath.org/sage_trac/attachment/ticket/12830/ecm-6.3.p6-p7.diff">ecm-6.3.p6-p7.diff: Diff between my p6 and p7 spkgs.  For reference / review only.</a> by leif at 20120419T14:19:13</li></ol>