FEX: Remove InlineSyscall and related flags

FEXCore no longer optimizes syscalls to be inline.

NFC, just avoids passing around a bunch of data structures for no
reason.

FEXCore/Source/Interface/IR/IR.json

@@ -138,7 +138,6 @@
     "FenceType": "FenceType",
     "RegisterClass": "RegClass",
     "CondClass": "CondClass",
-    "SyscallFlags": "FEXCore::IR::SyscallFlags",
     "SHA256Sum": "SHA256Sum",
     "MemOffsetType": "MemOffsetType",
     "BreakDefinition": "BreakDefinition",
@@ -314,7 +313,7 @@
       "CallbackReturn": {
         "HasSideEffects": true
       },
-      "GPR = Syscall GPR:$SyscallID, GPR:$Arg0, GPR:$Arg1, GPR:$Arg2, GPR:$Arg3, GPR:$Arg4, GPR:$Arg5, SyscallFlags:$Flags": {
+      "GPR = Syscall GPR:$SyscallID, GPR:$Arg0, GPR:$Arg1, GPR:$Arg2, GPR:$Arg3, GPR:$Arg4, GPR:$Arg5": {
         "HasSideEffects": true,
         "Desc": ["Dispatches a guest syscall through to the SyscallHandler class"
                 ],