Added more tests + fixed evstr issues

tests/ev_str/find_all_overlapping.c

@@ -0,0 +1,23 @@
+#define EV_STR_IMPLEMENTATION
+#include "ev_str.h"
+
+#include <assert.h>
+
+int main(void)
+{
+  evstring_view search_results[2];
+  evstring text = evstr("aaa");
+  evstring query = evstr("aa");
+
+  assert(evstring_findAll(text, query, search_results) == 2);
+
+  assert(search_results[0].data == text);
+  assert(search_results[0].len == 2);
+  assert(search_results[0].offset == 0);
+
+  assert(search_results[1].data == text);
+  assert(search_results[1].len == 2);
+  assert(search_results[1].offset == 1);
+
+  return 0;
+}