Update pnacl/DEPS to bring in stricter ABI checks for metadata

pnacl/driver/pnacl-ld.py

Index: pnacl/driver/pnacl-ld.py
diff --git a/pnacl/driver/pnacl-ld.py b/pnacl/driver/pnacl-ld.py
index dc57ee1f9d86855caf6095ce51a43cf6a91296fa..cd5a0d84e8a4d8adeecc54a308237a15942df5e7 100755
--- a/pnacl/driver/pnacl-ld.py
+++ b/pnacl/driver/pnacl-ld.py
@@ -378,13 +378,17 @@ def main(argv):
       # reintroduce ConstantExprs.  However, '-expand-getelementptr'
       # must follow '-expand-constant-expr' to expand the
       # getelementptr instructions it creates.
-      passes = ['-expand-constant-expr',
+      # We place '-strip-metadata' after optimization passes are run

[Mark Seaborn, 2013/04/26 21:36:45]

It would be clearer to omit "are run"

[jvoung (off chromium), 2013/04/26 22:54:51]

Done.

+      # since optimizations depend on the metadata.
+      passes = ['-strip-metadata',
+                '-expand-constant-expr',
                 '-expand-getelementptr']
       if (not env.getbool('DISABLE_ABI_CHECK') and
           not env.getbool('ALLOW_CXX_EXCEPTIONS') and
           len(native_objects) == 0):
         passes += ['-verify-pnaclabi-module',
-                   '-verify-pnaclabi-functions']
+                   '-verify-pnaclabi-functions',
+                   '-pnaclabi-allow-debug-metadata']

[Mark Seaborn, 2013/04/26 21:36:45]

Maybe comment "This option modifies the behaviour of -verify-pnaclabi-*".  It's
odd having it in a list called "passes" otherwise.

[jvoung (off chromium), 2013/04/26 22:54:51]

Done.

       chain.add(DoLLVMPasses(passes),
                 'expand_features_after_opt.' + bitcode_type)
   else: