Protect the oldest ID from races in the optimized path for read-only transactions.
Merge docs for metadata cursors into the cursors page.
AddressSanitizer: memcpy-param-overlap: memory ranges overlap

#1 0x49a1a8 in __wt_buf_set src/support/scratch.c:117
#2 0x4fbb10 in __wt_row_leaf_key_copy src/btree/row_key.c:115
#3 0x4cbc31 in __verify_row_leaf_key_order src/btree/bt_vrfy.c:511