strict aliasing violations.

Post-merge fix: include my_compiler.h before my_attribute.h
as the latter will undef __attribute__ if the compiler is not
GCC. Based on the compiler version, in my_compiler.h we know
for sure whether the aligned attribute is supported. Furthermore,
undefining attribute might cause bugs if some system header
uses it.

include/my_compiler.h:
  Drop aligned attribute support from Sun Studio C++ compiler
  as its not clear exactly which version of it supports the
  attribute.