[Autobackout][FunctionalRegression]Revert of change: 6230f52: Remat threshold increase

This change is to allow for bigger early rematerialization to avoid redundant spills.

(cherry picked from commit b6cbdcf)

Author: sys-igc

IGC/common/igc_flags.h

@@ -1807,7 +1807,7 @@ DECLARE_IGC_REGKEY(bool, DisableCanonizationWA, false,
                    "WA for A0 to inject shifts to canonize global and local pointers", true)
 DECLARE_IGC_REGKEY(bool, DisableEarlyRemat, false, "Disable quick remats to avoid some spills", true)
 DECLARE_IGC_REGKEY(bool, DisableLateRemat, false, "Disable quick remats to avoid some spills", true)
-DECLARE_IGC_REGKEY(DWORD, RematThreshold, 7, "Tunes how aggresively we should remat values into continuations", true)
+DECLARE_IGC_REGKEY(DWORD, RematThreshold, 6, "Tunes how aggresively we should remat values into continuations", true)
 DECLARE_IGC_REGKEY(bool, DisableCompactifySpills, false, "Just emit spill/fill at the point of def/use", true)
 DECLARE_IGC_REGKEY(bool, AllowSpillCompactionOnRetry, false, "Allow spill compaction on retry - may increase spills",
                    true)