The latter state is the only valid state in wcfs mode when pagefault
handler sees already loaded page in fileh->pagemap.

* master:
  bigfile: Note that ramh_alloc_page does not add the page to any lists
  bigfile: Unstub ram_close

It was already said there that allocated page is not associated with
fileh. However the code is doing more - it does not add the page to
ram->lru_list and (obviously) to fileh->dirty_pages lists.

Document that explicitly.

It should release resources associated with RAM. Make it call .ram_close
from RAM ops. Add corresponding .ram_close to ram_shmfs. This fixes
SHMFS_RAM->prefix leak.

* master:
  bigfile: Note that ramh_alloc_page does not add the page to any lists
  bigfile: Unstub ram_close
  bigfile/test/test_ram: Don't forget to free allocated Page structs
  bigfile: RAM must be explicitly free'ed after close
  bigfile/test: Don't forget to close opened RAM
  tests: TSAN no longer fails on test_virtmem
  tox: Don't duplicate setup.py on which for-tests dependencies we need
  3rdparty/ccan: Update

It was already said there that allocated page is not associated with
fileh. However the code is doing more - it does not add the page to
ram->lru_list and (obviously) to fileh->dirty_pages lists.

Document that explicitly.

It should release resources associated with RAM. Make it cal .ram_close
from RAM ops. Add corresponding .ram_close to ram_shmfs. This fixes
SHMFS_RAM->prefix leak.

test_ram is low-level test that tests RAM pages allocation/mmapping.
As allocated pages are not integrated with virtmem (not added to any
file mapping and RAM->lru_list) the Page structs have to be explicitly
freed. Fixes e.g.

	Direct leak of 80 byte(s) in 1 object(s) allocated from:
	    #0 0x7ff29af46518 in calloc (/usr/lib/x86_64-linux-gnu/libasan.so.5+0xe9518)
	    #1 0x56131dc22289 in zalloc include/wendelin/utils.h:67
	    #2 0x56131dc225d6 in ramh_alloc_page bigfile/tests/../ram.c:41
	    #3 0x56131dc2a19e in main bigfile/tests/test_ram.c:130
	    #4 0x7ff29ac9f09a in __libc_start_main ../csu/libc-start.c:308