Linking issue with gcc-4.9, but not gcc-4.8

Linking issue with gcc-4.9, but not gcc-4.8

[Karl Apsite]

Ahoy there!

I was attempting to compile Xen from branches: `master`, and `stable-4.5`  I had
some trouble initially, as Ubuntu 12.04 defaults to an old version of gcc.  I
updated gcc to 4.9 from the toolchain ppa, and was NOT able to compile Xen on
either branch.  Installing and configuring gcc 4.8 allows Xen to compile
successfully.

Log (tail) when compiling with gcc 4.9
https://gist.github.com/CptSpaceToaster/467ce2625dcb6b5d2ace#file-gistfile1-txt-L28

Line 43 in this makefile that has some trouble:
$(XEN_REPO)/tools/common/libfsimage/common/Makefile
http://xenbits.xen.org/gitweb/?p=xen.git;a=blob;f=tools/libfsimage/common/Makefile;h=fb306f4e33803d0e8593081269d1f96a7462d9e1;hb=HEAD#l43

The `-Wl,libfsimage.so.$(MAJOR)` seems suspect.  But I wasn't successful when I
tried tinkering with it for a bit.  Does anyone have any idea what might be
going wrong here?