Make a gyp file for the pnacl_irt_shim.

build/all.gyp

Index: build/all.gyp
===================================================================
--- build/all.gyp	(revision 7377)
+++ build/all.gyp	(working copy)
@@ -44,6 +44,15 @@
             '../src/trusted/validator_x86/validator_x86.gyp:*',
           ],
         }],
+         ['target_arch=="x64" or OS=="win"', {
+           # This library is only for x86-64 for now
+           # (the windows build always includes 64-bit).
+           # We may introduce a dummy shim to make it uniform.
+           'dependencies': [
+#             '../src/untrusted/pnacl_irt_shim/pnacl_irt_shim.gyp:*',
+             '../../ppapi/pnacl_irt_shim.gyp:*',
+           ],
+         }],
         ['OS=="win" and nacl_standalone==0', {
           'dependencies': [
             '../src/trusted/handle_pass/handle_pass.gyp:*',