I ran test_strtod using: ./python -m test -M 6G test_strtod. The test passed successfully on my 64-bit Linux box. But there is an issue with the announced memory limit: it looks closer to 6 GB than 5 GB.

$ ./python -m test -M 6G -v test_strtod
== CPython 3.4.0b1 (default:9c7ab3e68243, Nov 26 2013, 17:24:05) [GCC 4.7.2 20121109 (Red Hat 4.7.2-8)]
==   Linux-3.9.4-200.fc18.x86_64-x86_64-with-fedora-18-Spherical_Cow little-endian
==   hash algorithm: siphash24 64bit
==   /home/haypo/prog/python/default/build/test_python_2997
Testing with flags: sys.flags(debug=0, inspect=0, interactive=0, optimize=0, dont_write_bytecode=0, no_user_site=0, no_site=0, ignore_environment=0, verbose=0, bytes_warning=0, quiet=0, hash_randomization=1, isolated=0)
[1/1] test_strtod
test_bigcomp (test.test_strtod.StrtodTests) ... ok
test_boundaries (test.test_strtod.StrtodTests) ... ok
test_halfway_cases (test.test_strtod.StrtodTests) ... ok
test_large_exponents (test.test_strtod.StrtodTests) ... ok
test_oversized_digit_strings (test.test_strtod.StrtodTests) ... 
 ... expected peak memory use: 5.0G
 ... process data size: 2.1G
(...)
 ... process data size: 4.1G
(...)
 ... process data size: 6.2G
(...)
 ... process data size: 2.1G
ok
test_parsing (test.test_strtod.StrtodTests) ... ok
test_particular (test.test_strtod.StrtodTests) ... ok
test_short_halfway_cases (test.test_strtod.StrtodTests) ... ok
test_underflow_boundary (test.test_strtod.StrtodTests) ... ok

----------------------------------------------------------------------
Ran 9 tests in 63.871s

OK
1 test OK.