[Hexagon] Add REQUIRES: asserts to test

This test uses -debug-only, so needs an assertion-enabled build.

Author: nikic

llvm/test/CodeGen/Hexagon/insert-big.ll

@@ -14,6 +14,8 @@
 ; RUN: llc -O2 -mtriple=hexagon -insert-max-ifmap=4 -debug-only=hexinsert -stop-after hexinsert < %s 2>&1 | FileCheck %s
 ; RUN: llc -O2 -mtriple=hexagon -insert-max-ifmap=5 -debug-only=hexinsert -stop-after hexinsert < %s 2>&1 | FileCheck %s
 
+; REQUIRES: asserts
+
 define i32 @f(i32 %0, i32 %1, i32 %2) {
 entry:
   switch i32 %0, label %common.ret1 [