Make CommandSelLdrTestNacl ignore --nacl_glibc for tests in trusted code
Make CommandSelLdrTestNacl ignore --nacl_glibc for tests in trusted code

CommandSelLdrTestNacl expects to be used in untrusted code tests (nacl_env).
But it is also used in src/trusted/service_runtime/build.scons (base_env).
In that context, the --nacl_glibc modifications to the sel_ldr command
lines do not make sense.

This went unnoticed because of the five relevant uses of this method,
one is specifically blacklisted for glibc (run_fuzz_nullptr_test), three
are in medium_tests, which do not (yet) get run for glibc, and the one
that does run is sel_ldr_exe_not_found_test, which is expected to fail
for a file not found.  It indeed did fail for a file not found, but it
was for the file "/runnable-ld.so", which is what got tried because
${NACL_SDK_LIB} is not set (and thus substitutes as empty) in base_env.

We change it to ignore the --nacl_glibc switch when it's being used in
base_env rather than nacl_env.  This makes sel_ldr_exe_not_found_test
pass by failing as expected, "name_of_file_that_does_not_exist.nexe"
not being found rather than "/runnable-ld.so" not being found.

BUG=none
TEST=none

R=ncbray@google.com,noelallen@google.com,mseaborn@google.com,bsy@google.com

Review URL: http://codereview.chromium.org/7065071

git-svn-id: 721b910a23eff8a86f00c8fd261a7587cddf18f8@5560 fcba33aa-ac0c-11dd-b9e7-8d5594d729c2

sbc100/native_client,nacl-webkit/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,sbc100/native_client,nacl-webkit/native_client,sbc100/native_client,sbc100/native_client