Use Intrinsic::getDeclaration to obtain the nacl_read_tp intrinsic

include/llvm/IR/Intrinsics.td

 //===- Intrinsics.td - Defines all LLVM intrinsics ---------*- tablegen -*-===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file defines properties of all LLVM intrinsics.
@@ skipping 461 matching lines @@
 
 // @LOCALMOD-BEGIN
 //===----------------------- Native Client Intrinsics ---------------------===//
 // NaCl-specific setjmp/longjmp intrinsics.
 // See https://code.google.com/p/nativeclient/issues/detail?id=3429
 def int_nacl_setjmp   : Intrinsic<[llvm_i32_ty],  [llvm_ptr_ty]>;
 def int_nacl_longjmp  : Intrinsic<[], [llvm_ptr_ty, llvm_i32_ty],
                                   [IntrNoReturn]>;
 
 // Fast built-in version of NaCl's tls_get() IRT interface.
-def int_nacl_read_tp : Intrinsic<[llvm_ptr_ty], [], [IntrNoMem]>,
-                       GCCBuiltin<"__builtin_nacl_read_tp">;
+def int_nacl_read_tp : Intrinsic<[llvm_ptr_ty], [], [IntrNoMem]>;
 
 // The following intrinsics provide target-specific implementations of
 // the interface in native_client/src/untrusted/nacl/tls_params.h.
 // The intrinsic names are basically the functions there without the
 // leading underscores.
 def int_nacl_tp_tls_offset : Intrinsic<[llvm_i32_ty], [llvm_i32_ty]>,
                              GCCBuiltin<"__builtin_nacl_tp_tls_offset">;
 def int_nacl_tp_tdb_offset : Intrinsic<[llvm_i32_ty], [llvm_i32_ty]>,
                              GCCBuiltin<"__builtin_nacl_tp_tdb_offset">;
 
 // The following intrinsic provides a target-specific constant value to
 // indicate the target platform compiled to.  The enum values are enumerated
 // pnaclintrin.h.
 def int_nacl_target_arch : Intrinsic<[llvm_i32_ty], []>,
                             GCCBuiltin<"__builtin_nacl_target_arch">;
 // @LOCALMOD-END
 
 //===----------------------------------------------------------------------===//
 // Target-specific intrinsics
 //===----------------------------------------------------------------------===//
 
 include "llvm/IR/IntrinsicsPowerPC.td"
 include "llvm/IR/IntrinsicsX86.td"
 include "llvm/IR/IntrinsicsARM.td"
 include "llvm/IR/IntrinsicsXCore.td"
 include "llvm/IR/IntrinsicsHexagon.td"
 include "llvm/IR/IntrinsicsNVVM.td"
 include "llvm/IR/IntrinsicsMips.td"
 include "llvm/IR/IntrinsicsR600.td"