Enable 1-step elf by default

Change-Id: I3df543de65df1a1aed1bb3368cdba95ce0ceb291

Author: pratikashar

IGC/common/igc_flags.def

@@ -322,7 +322,7 @@ DECLARE_IGC_REGKEY(bool, ForceSubroutineForEmulation,   false,  "Force subroutin
 DECLARE_IGC_REGKEY(int, ByPassAllocaSizeHeuristic,   0,  "Force some Alloca to pass the pressure heuristic until the given size")
 DECLARE_IGC_REGKEY(DWORD, MemOptWindowSize,   150,  "Change the size of the window in which we allow load/stores to be coalesced. We keep it limited in order to avoid creating long liveranges. Default value is 150")
 DECLARE_IGC_REGKEY(bool, ForceNoFP64bRegioning, false, "force regioning rules for FP and 64b FPU instructions")
-DECLARE_IGC_REGKEY(bool, EnableOneStepElf, false, "Enable generation of direct elf mapping src->Gen ISA")
+DECLARE_IGC_REGKEY(bool, EnableOneStepElf, true, "Enable generation of direct elf mapping src->Gen ISA")
 
 DECLARE_IGC_GROUP("Generating precompiled headers")
 DECLARE_IGC_REGKEY(bool, ApplyConservativeRastWAHeader, true,