[sql] Import SQLite 3.17.0.

third_party/sqlite/src/ext/fts3/unicode/mkunicode.tcl

Index: third_party/sqlite/src/ext/fts3/unicode/mkunicode.tcl
diff --git a/third_party/sqlite/src/ext/fts3/unicode/mkunicode.tcl b/third_party/sqlite/src/ext/fts3/unicode/mkunicode.tcl
index a2e9b1da29316fcd28b753627d6250bb761d50e7..aafb4e9f9bfa94ec0996a0e21d97923868c8ef35 100644
--- a/third_party/sqlite/src/ext/fts3/unicode/mkunicode.tcl
+++ b/third_party/sqlite/src/ext/fts3/unicode/mkunicode.tcl
@@ -226,9 +226,9 @@ proc print_isalnum {zFunc lRange} {
   an_print_range_array $lRange
   an_print_ascii_bitmap $lRange
   puts {
-  if( c<128 ){
+  if( (unsigned int)c<128 ){
     return ( (aAscii[c >> 5] & (1 << (c & 0x001F)))==0 );
-  }else if( c<(1<<22) ){
+  }else if( (unsigned int)c<(1<<22) ){
     unsigned int key = (((unsigned int)c)<<10) | 0x000003FF;
     int iRes = 0;
     int iHi = sizeof(aEntry)/sizeof(aEntry[0]) - 1;