NonSFI Mode: Make hello_world test run with nonsfi_nacl=1 bitcode=1 pnacl_generate_pexe=0.

SConstruct

Index: SConstruct
diff --git a/SConstruct b/SConstruct
index a9ba543187681bb3eadc01386ca55acb32425ae9..bbae24cbb3f60bda190d48caaff39d9d59a91201 100755
--- a/SConstruct
+++ b/SConstruct
@@ -3700,7 +3700,9 @@ if nacl_env.Bit('nonsfi_nacl'):
   # involves using inline assembly, this requires turning off the PNaCl ABI
   # checker.
   nacl_env.SetBits('nonstable_bitcode')
-  nacl_env.Append(LINKFLAGS=['--pnacl-disable-abi-check'])
+  nacl_env.Append(LINKFLAGS=['--pnacl-disable-abi-check',
+                             '--pnacl-allow-native',

[Mark Seaborn, 2014/09/25 17:08:09]

So this fails on the bots, with:
pnacl-clang++: --pnacl-allow-native without -arch is not meaningful.

'--pnacl-allow-native' is required to use '-Wt,--noirt'.  '-Wt,--noirt' is also
rejected when linking a pexe.

How about doing this:

+  if nacl_env.Bit('pnacl_generate_pexe'):
+    # Not-IRT-using non-SFI code uses Linux syscalls directly.  Since this
+    # involves using inline assembly, this requires turning off the PNaCl
+    # ABI checker.
+    nacl_env.SetBits('nonstable_bitcode')
+    nacl_env.Append(LINKFLAGS=['--pnacl-disable-abi-check'])
+    # Tell the PNaCl translator to link a Linux executable.
+    nacl_env.Append(TRANSLATEFLAGS=['--noirt'])
+  else:
+    nacl_env.Append(LINKFLAGS=['--pnacl-allow-native', '-Wt,--noirt'])

This is also more self-documenting, since it indicates which flags are required
in the pnacl_generate_pexe=0,1 cases.

[Junichi Uekawa, 2014/09/25 23:05:07]

Done.

+                             '-Wt,--noirt'])
   # Tell the PNaCl translator to link a Linux executable.
   nacl_env.Append(TRANSLATEFLAGS=['--noirt'])