[WebAssembly] Add IntrNoReturn property to throw/rethrow intrinsics

[aheejin]

• style change

[aheejin]

• style fix again

[aheejin]

• Add a separating line

include/llvm/IR/IntrinsicsWebAssembly.td

def int_wasm_mem_grow : Intrinsic<[llvm_anyint_ty],
                                   [llvm_i32_ty, LLVMMatchType<0>],
                                   []>;
 
 // These are the existing names, which are currently official, but expected
 // to be deprecated in the future. They also lack the immediate field.
 def int_wasm_current_memory : Intrinsic<[llvm_anyint_ty], [], [IntrReadMem]>;
 def int_wasm_grow_memory : Intrinsic<[llvm_anyint_ty], [LLVMMatchType<0>], []>;
 
+//===----------------------------------------------------------------------===//
 // Exception handling intrinsics
-def int_wasm_throw: Intrinsic<[], [llvm_i32_ty, llvm_ptr_ty], [Throws]>;
-def int_wasm_rethrow: Intrinsic<[], [], [Throws]>;
+//===----------------------------------------------------------------------===//
 
+// throw / rethrow
+def int_wasm_throw : Intrinsic<[], [llvm_i32_ty, llvm_ptr_ty],
+                               [Throws, IntrNoReturn]>;
+def int_wasm_rethrow : Intrinsic<[], [], [Throws, IntrNoReturn]>;
 }