AMDGPU: Add willreturn to sendmsg intrinsics (#125014)

Author: arsenm

llvm/include/llvm/IR/IntrinsicsAMDGPU.td

@@ -237,7 +237,7 @@ def int_amdgcn_reloc_constant : DefaultAttrsIntrinsic<
 // the second one is copied to m0
 def int_amdgcn_s_sendmsg : ClangBuiltin<"__builtin_amdgcn_s_sendmsg">,
   Intrinsic <[], [llvm_i32_ty, llvm_i32_ty],
-  [ImmArg<ArgIndex<0>>, IntrNoMem, IntrHasSideEffects]>;
+  [ImmArg<ArgIndex<0>>, IntrNoMem, IntrHasSideEffects, IntrWillReturn]>;
 def int_amdgcn_s_sendmsghalt : ClangBuiltin<"__builtin_amdgcn_s_sendmsghalt">,
   Intrinsic <[], [llvm_i32_ty, llvm_i32_ty],
   [ImmArg<ArgIndex<0>>, IntrNoMem, IntrHasSideEffects]>;
@@ -246,7 +246,7 @@ def int_amdgcn_s_sendmsghalt : ClangBuiltin<"__builtin_amdgcn_s_sendmsghalt">,
 // gfx11 intrinsic
 // The first parameter is s_sendmsg immediate (i16). Return type is i32 or i64.
 def int_amdgcn_s_sendmsg_rtn : Intrinsic <[llvm_anyint_ty], [llvm_i32_ty],
-  [ImmArg<ArgIndex<0>>, IntrNoMem, IntrHasSideEffects]>;
+  [ImmArg<ArgIndex<0>>, IntrNoMem, IntrHasSideEffects, IntrWillReturn]>;
 
 // Vanilla workgroup sync-barrier
 def int_amdgcn_s_barrier : ClangBuiltin<"__builtin_amdgcn_s_barrier">,