update global.c

add function notes
Merge pull request #1 from HuiLi/master

merge update
Update mem3.c
Update mem3.c
Update pager.c
Update mem5.c
Update fts3_hash.c
Update sqliteInt.h
Update fts3_hash.c
Update fts3_hash.c
Update fts3_hash.c
Update mem3.c
vdbeaux部分源代码分析

vdbeaux部分源代码分析2317-2764
Update pager.c
Update pager.c
Update sqliteInt.h
Merge pull request #2 from HuiLi/master

merge update
Update vdbe.c
2
Update sqliteInt.h