pgsql: Don't assume that 'char' is signed.

Don't assume that 'char' is signed.

On some platforms, notably ARM and PowerPC, 'char' is unsigned by
default. This fixes an assertion failure at WAL replay on such platforms.

Reported by Noah Misch. Backpatch to 9.5, where this was broken.

Branch
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REL9_5_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/1b7f125bf7e74fb3b128b3bcbe593d9e7327ff50

Modified Files
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src/include/access/spgist_private.h |    2 +-
1 file changed, 1 insertion(+), 1 deletion(-)