Add NO_EXEC_STACK_DIRECTIVE to xray assembly files.

[saugustine]

Summary

Add NO_EXEC_STACK_DIRECTIVE to xray assembly files

[dberris]

LGTM -- thanks @saugustine!

lib/xray/xray_trampoline_AArch64.S

+#include "../builtins/assembly.h"
+
     .text
     /* The variable containing the handler function pointer */
     .global _ZN6__xray19XRayPatchedFunctionE
     /* Word-aligned function entry point */
     .p2align 2
     /* Let C/C++ see the symbol */
     .global __xray_FunctionEntry
     .type __xray_FunctionEntry, %function
__xray_FunctionExit:
     BLR X2
 FunctionExit_restore:
     LDR Q0, [SP], #16
     LDP X7, X30, [SP], #16
     LDP X5, X6, [SP], #16
     LDP X3, X4, [SP], #16
     LDP X1, X2, [SP], #16
     RET
+
+NO_EXEC_STACK_DIRECTIVE

lib/xray/xray_trampoline_arm.S

+#include "../builtins/assembly.h"
+
     .syntax unified
     .arch armv6t2
     .fpu vfpv2
     .code 32
     .global _ZN6__xray19XRayPatchedFunctionE
     @ Word-aligned function entry point
     .p2align 2
     @ Let C/C++ see the symbol
__xray_FunctionExit:
     @ 1 means that we are tracing an exit event
     MOV r1, #1
     @ Call the handler with 2 parameters in r0 and r1
     BLX r2
 FunctionExit_restore:
     @ Restore the floating-point return value of the instrumented function
     VPOP {d0}
     POP {r1-r3,pc}
+
+NO_EXEC_STACK_DIRECTIVE

lib/xray/xray_trampoline_x86_64.S

 //===-- xray_trampoline_x86.s -----------------------------------*- ASM -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file is a part of XRay, a dynamic runtime instrumentation system.
 //
 // This implements the X86-specific assembler for the trampolines.
 //
 //===----------------------------------------------------------------------===//
 
+#include "../builtins/assembly.h"
+
 .macro SAVE_REGISTERS
   subq $200, %rsp
   movupd  %xmm0, 184(%rsp)
   movupd  %xmm1, 168(%rsp)
   movupd  %xmm2, 152(%rsp)
   movupd  %xmm3, 136(%rsp)
   movupd  %xmm4, 120(%rsp)
   movupd  %xmm5, 104(%rsp)

 
 .Ltmp4:
   RESTORE_REGISTERS
   popq  %rbp
   retq
 .Ltmp5:
   .size __xray_FunctionTailExit, .Ltmp5-__xray_FunctionTailExit
   .cfi_endproc
+
+NO_EXEC_STACK_DIRECTIVE