glibc: fixup libm.a

Now it's not an actual archive but a linker script, and the absolute
paths in there were broken due to moving *.a into $static.
Let's fix this up in all *.a in case there are more in future.

pkgs/development/libraries/glibc/default.nix

@@ -91,6 +91,9 @@ in
       mkdir -p $static/lib
       mv $out/lib/*.a $static/lib
       mv $static/lib/lib*_nonshared.a $out/lib
+      # Some of *.a files are linker scripts where moving broke the paths.
+      sed "/^GROUP/s|$out/lib/lib|$static/lib/lib|g" \
+        -i "$static"/lib/*.a
 
       # Work around a Nix bug: hard links across outputs cause a build failure.
       cp $bin/bin/getconf $bin/bin/getconf_