Fix pnacl_support_extension null build on linux/mac (no longer have libgcc_eh.a).

The libgcc_eh.a file is no longer in the translator tarball
possibly after NaCl revision:

1fceb45: (dschuff) Wrap PNaCl sandboxed translator build in toolchain_build recipe

Cr-Commit-Position: refs/heads/master@{#312891}, fixed
this for windows builds, but not linux / mac.

Review URL: https://codereview.chromium.org/879803002

Cr-Commit-Position: refs/heads/master@{#313192}
1 file changed