The creation of the primary key does not work. We will have to flag
externally stored columns and copy the externally stored part from
the old table.
row_build_index_for_mysql(): Rename to row_merge_build_indexes().
Move from row0mysql.c to row0merge.c.
Remove private declarations from row0merge.h. Make many functions static
in row0merge.c.
cmp_rec_rec_simple(): A new comparison function.
dict_index_get_min_size(): New function.
OS_FILE_FROM_FD(fd): A macro for converting from int to os_file_t.
rec_convert_dtuple_to_rec_comp(): Make the interface lower-level.
rec_get_converted_size_comp(): Return also extra_size.
UT_SORT_FUNCTION_BODY(): Remove reference to an obsolete test program.
row_rec_to_index_entry_low(): New function.
row0merge.c: Implement merge sort based on file streams instead of
fixed-size blocks. Sort the small blocks as arrays of dfield_t*,
because it is faster than invoking rec_get_offsets() for every
comparison.
and modify some functions to return const pointers. Add const qualifiers
to local variable declarations or casts to remove the const qualifier
in those places where write access is needed.
