Upgrade to pcre2 version 10.31.

Bug: N/A
Test: builds and boots, getprop -Z works
Change-Id: I2fbda9427edc9e5d966333a567b50539e17ed48d
diff --git a/dist2/PrepareRelease b/dist2/PrepareRelease
index 114fce0..9aa6b7d 100755
--- a/dist2/PrepareRelease
+++ b/dist2/PrepareRelease
@@ -66,7 +66,7 @@
 echo "Making pcre2.txt"
 for file in pcre2 pcre2api pcre2build pcre2callout pcre2compat pcre2jit \
             pcre2limits pcre2matching pcre2partial pcre2pattern pcre2perform \
-            pcre2posix pcre2sample pcre2serialize pcre2stack pcre2syntax \
+            pcre2posix pcre2sample pcre2serialize pcre2syntax \
             pcre2unicode ; do
   echo "  Processing $file.3"
   nroff -c -man $file.3 >$file.rawtxt
@@ -146,7 +146,6 @@
   toc=-toc
   if [ `expr $base : '.*_'` -ne 0 ] ; then toc="" ; fi
   if [ "$base" = "pcre2sample" ]  || \
-     [ "$base" = "pcre2stack" ]   || \
      [ "$base" = "pcre2compat" ]  || \
      [ "$base" = "pcre2limits" ]  || \
      [ "$base" = "pcre2unicode" ] ; then
@@ -197,8 +196,10 @@
   src/pcre2_compile.c \
   src/pcre2_config.c \
   src/pcre2_context.c \
+  src/pcre2_convert.c \
   src/pcre2_dfa_match.c \
   src/pcre2_error.c \
+  src/pcre2_extuni.c \
   src/pcre2_find_bracket.c \
   src/pcre2_internal.h \
   src/pcre2_intmodedep.h \