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.

Source/Windows/ARM64EC/Module.cpp

@@ -581,10 +581,6 @@ public:
     JumpSetStack(KiUserExceptionDispatcher, reinterpret_cast<uintptr_t>(&DispatchArgs));
   }
 
-  FEXCore::HLE::SyscallABI GetSyscallABI(uint64_t Syscall) override {
-    return {.NumArgs = 0, .HasReturn = false, .HostSyscallNumber = -1};
-  }
-
   std::optional<FEXCore::ExecutableFileSectionInfo> LookupExecutableFileSection(FEXCore::Core::InternalThreadState&, uint64_t) override {
     return std::nullopt;
   }