[hexagon] Require "asserts" build for widen-not-load test (#117414)
This test fails on the `clang-x64-windows-msvc` builder:
.---command stderr------------
|
C:\b\slave\clang-x64-windows-msvc\llvm-project\llvm\test\CodeGen\Hexagon\widen-not-load.ll:7:16:
error: CHECK-LABEL: expected string not found in input
| ; CHECK-LABEL: test1
| ^
| <stdin>:1:1: note: scanning from here
| llc.exe: Unknown command line argument
'-debug-only=hexagon-load-store-widening'. Try:
'c:\b\slave\clang-x64-windows-msvc\build\stage1\bin\llc.exe --help'
| ^
| <stdin>:1:35: note: possible intended match here
| llc.exe: Unknown command line argument
'-debug-only=hexagon-load-store-widening'. Try:
'c:\b\slave\clang-x64-windows-msvc\build\stage1\bin\llc.exe --help'
| ^