Suppress compiler warnings in readfuncs.c.
Suppress compiler warnings in readfuncs.c.

Commit 7357558fc8866e3a449aa9473c419b593d67b5b6 introduced "(void) token;"
into the READ_TEMP_LOCALS() macro, to suppress complaints from gcc 4.6
when the value of token was not used anywhere in a particular node-read
function.  However, this just moved the warning around: inspection of
buildfarm results shows that some compilers are now complaining that token
is being read before it's set.  Revert the READ_TEMP_LOCALS() macro change
and instead put "(void) token;" into READ_NODE_FIELD(), which is the
principal culprit for cases where the warning might occur.  In principle we
might need the same in READ_BITMAPSET_FIELD() and/or READ_LOCATION_FIELD(),
but it seems unlikely that a node would consist only of such fields, so
I'll leave them alone for now.

yazun/postgres-xl,greenplum-db/gpdb,xinzweb/gpdb,adam8157/gpdb,adam8157/gpdb,ovr/postgres-xl,adam8157/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,techdragon/Postgres-XL,Postgres-XL/Postgres-XL,xinzweb/gpdb,50wu/gpdb,techdragon/Postgres-XL,zeroae/postgres-xl,ashwinstar/gpdb,yazun/postgres-xl,jmcatamney/gpdb,Postgres-XL/Postgres-XL,lisakowen/gpdb,ashwinstar/gpdb,oberstet/postgres-xl,pavanvd/postgres-xl,techdragon/Postgres-XL,jmcatamney/gpdb,greenplum-db/gpdb,ovr/postgres-xl,ovr/postgres-xl,oberstet/postgres-xl,ashwinstar/gpdb,jmcatamney/gpdb,adam8157/gpdb,50wu/gpdb,jmcatamney/gpdb,xinzweb/gpdb,jmcatamney/gpdb,Postgres-XL/Postgres-XL,greenplum-db/gpdb,pavanvd/postgres-xl,ashwinstar/gpdb,50wu/gpdb,yazun/postgres-xl,oberstet/postgres-xl,50wu/gpdb,ovr/postgres-xl,ovr/postgres-xl,50wu/gpdb,lisakowen/gpdb,lisakowen/gpdb,zeroae/postgres-xl,techdragon/Postgres-XL,lisakowen/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,pavanvd/postgres-xl,oberstet/postgres-xl,yazun/postgres-xl,ashwinstar/gpdb,xinzweb/gpdb,zeroae/postgres-xl,50wu/gpdb,pavanvd/postgres-xl,xinzweb/gpdb,adam8157/gpdb,xinzweb/gpdb,jmcatamney/gpdb,zeroae/postgres-xl,adam8157/gpdb,Postgres-XL/Postgres-XL,lisakowen/gpdb,lisakowen/gpdb,greenplum-db/gpdb,adam8157/gpdb,zeroae/postgres-xl,adam8157/gpdb,techdragon/Postgres-XL,yazun/postgres-xl,ashwinstar/gpdb,Postgres-XL/Postgres-XL,50wu/gpdb,pavanvd/postgres-xl,lisakowen/gpdb,lisakowen/gpdb,xinzweb/gpdb,ashwinstar/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,oberstet/postgres-xl,50wu/gpdb,xinzweb/gpdb,greenplum-db/gpdb