results_test: fix output: print atom indexes, not file pos

allow diff API users to atomize files separately This is a breaking API change (not that we care about that at this point). This can avoid redundant work spent on atomizing a file multiple times. There are use cases where one particular file must be compared to other files over and over again, such as when blaming file history. The old API gave access to both versions of the file to the atomizer just in case a future atomizer implementation needs this. This can still be achieved by passing a second file via the atomizer's private data pointer.

fix another format string issue in results_test.c Cast ARRAYLIST_IDX result to unsigned long and use %lu in the format string. Clang 10.0.1 complained as follows: results_test.c:148:9: warning: format specifies type 'int' but the argument has type 'long' [-Wformat] ARRAYLIST_IDX(c, result->chunks), ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

fix a format string issue in results_test.c Use explicit casts to long long and use %lld in the format string. Clang 10.0.1 complained as follows: results_test.c:78:9: warning: format specifies type 'int' but the argument has type 'long long' [-Wformat] c->left_start ? c->left_start->pos : -1, ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

add results_test.c