ARM C library is really good at optimising out calls to underlying
seek. The only ones we were actually detecting in the empty file case
were the ones that the default FileHandle::size() made itself during
the SEEK_END case.
When we implement TestFile::size() directly, we will no longer see
a single seek call from the ARM C library in the empty file case, so
remove those tests.
Beef up the non-empty file case, adding checks that we are making
underlying read+write calls in the correct position, as a proxy for
direct checks for underlying seek being called.
mbed.h was added in test, via greentea and utest header files. 'mbed.h' is removed
from header files and required header file and namespace is added to CPP/C files
Martin Kojtal
RAJKUMAR KANAGARAJ
Kevin Bracey
Deepika
Maciej Bocianski