add getprotobyname and associated functions from netdb.h. Add test_getprotobyname.c test suite and update test_sockets.py to include test_getprotobyname. ./runner.py sockets.test_getprotobyname completes successfully
in getprotoent return 0 rather than null if we reach eof in our protocol database
replace PROTOCOL_LIST and PROTOCOL_MAP with a Protocols object containing a list and a map instance
updated simd.js to fix nan canonicalization issue for bitcasts
fix accidental rewrite of original url source of simd.js
Run test with single source input and output files

This commit allows us to run a test when it requires only
a single source and expected output file.
Use do_run_from_file() for test_hello_world
Use do_run_from_file() for test_intvars
Use do_run_from_file() for test_sintvars
Use do_run_from_file() for test_i64_b
Use do_run_from_file() for test_i64_cmp
Use do_run_from_file() for test_i64_cmp2
Use do_run_from_file() for test_i64_double
Use do_run_from_file() for test_i64_umul
Use do_run_from_file() for test_i64_llabs
Use do_run_from_file() for test_i64_zextneg
Use do_run_from_file() for test_i64_7z
Use do_run_from_file() for test_i64_i16
Use do_run_from_file() for test_i64_qdouble
Use do_run_from_file() for test_i64_varargs