Description:
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pg_update() fails to store infinite values.

Test script:
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$dbh = pg_connect("dbname=test");
pg_update($dbh, "test", ["ping" => INF], ["id" => 42]);
pg_update($dbh, "test", ["ping" => "INF"], ["id" => 42]);



Expected result:
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pg_update() (and pg_insert()) should be able to store infinite values (INF and -INF).

In PostgreSQL itself it works:
UPDATE test SET ping = 'INF' WHERE id = 42;

Actual result:
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PHP Warning:  pg_update(): ERROR:  column "inf" does not exist
LINE 1: UPDATE "test" SET "ping"=INF WHERE "id"=42...
                                    ^
 in Command line code on line 1

PHP Notice:  pg_update(): 'INF' does not match with '^([+-]{0,1}[0-9]+)|([+-]{0,1}[0-9]*[\.][0-9]+)|([+-]{0,1}[0-9]+[\.][0-9]*)$' in Command line code on line 1
PHP Notice:  pg_update(): Expects NULL, string, long or double value for PostgreSQL 'float4' (ping) in Command line code on line 1