Merge branch 'jk/asan-bonanza'

Various issues detected by Asan have been corrected.

* jk/asan-bonanza:
  t: enable ASan's strict_string_checks option
  fsck: avoid parse_timestamp() on buffer that isn't NUL-terminated
  fsck: remove redundant date timestamp check
  fsck: avoid strcspn() in fsck_ident()
  fsck: assert newline presence in fsck_ident()
  cache-tree: avoid strtol() on non-string buffer
  Makefile: turn on NO_MMAP when building with ASan
  pack-bitmap: handle name-hash lookups in incremental bitmaps
  compat/mmap: mark unused argument in git_munmap()

t/test-lib.sh

@@ -77,6 +77,7 @@ prepend_var GIT_SAN_OPTIONS : strip_path_prefix="$GIT_BUILD_DIR/"
 # want that one to complain to stderr).
 prepend_var ASAN_OPTIONS : $GIT_SAN_OPTIONS
 prepend_var ASAN_OPTIONS : detect_leaks=0
+prepend_var ASAN_OPTIONS : strict_string_checks=1
 export ASAN_OPTIONS
 
 prepend_var LSAN_OPTIONS : $GIT_SAN_OPTIONS