Fix compilation of GCC 4.9 on SmartOS.

Fix ld-solaris-wrapper never calling ld (since gcc->cc-wrapper refactor).

pkgs/build-support/cc-wrapper/default.nix

@@ -145,7 +145,7 @@ stdenv.mkDerivation {
     + optionalString (stdenv.isSunOS && nativePrefix != "") ''
       # Solaris needs an additional ld wrapper.
       ldPath="${nativePrefix}/bin"
-      ld="$out/bin/ld-solaris"
+      exec="$ldPath/ld"
       wrap ld-solaris ${./ld-solaris-wrapper.sh}
     '')
 

pkgs/build-support/cc-wrapper/ld-solaris-wrapper.sh

@@ -6,7 +6,7 @@ set -u
 # I've also tried adding -z direct and -z lazyload, but it gave too many problems with C++ exceptions :'(
 # Also made sure libgcc would not be lazy-loaded, as suggested here: https://www.illumos.org/issues/2534#note-3
 #   but still no success.
-cmd="@prog@ -z ignore"
+cmd="@ld@ -z ignore"
 
 args=("$@");