Revert "test suite fixes to prep for enabling additional warnings"

[slavapestov]

Reverts #274

I believe this broke the build, eg https://ci.swift.org//job/oss-swift-incremental-RA-linux-ubuntu-14_04/3550/consoleFull#1160775376ee1a197b-acac-4b17-83cf-a53b95139a76

/home/buildnode/disk2/workspace/oss-swift-incremental-RA-linux-ubuntu-14_04/swift-corelibs-libdispatch/tests/bsdtests.h:72:72: error: expected function body after function declarator
void test_ptr_notnull_format(const void *ptr, const char *format, ...) __printflike(2, 3);
                                                                       ^
/home/buildnode/disk2/workspace/oss-swift-incremental-RA-linux-ubuntu-14_04/swift-corelibs-libdispatch/tests/bsdtests.h:80:89: error: expected function body after function declarator
void test_ptr_format(const void* actual, const void* expected, const char *format, ...) __printflike(3,4);
                                                                                        ^

[das]

@slavapestov thanks, sorry about that, should have run that branch through the CI before merging