[AMD] Add check to fix test_store_cache_modifier for MI300 (triton-lang#4726)

Co-authored-by: Lei Zhang <[email protected]>

Author: CRobeck

python/test/unit/language/test_core.py

@@ -3924,6 +3924,8 @@ def _kernel(dst, src, CACHE: tl.constexpr):
         cs_cache_modifier_str = 'nt'
         wt_cache_modifier_str = 'sc0 sc1'
         global_store_line = [line for line in amdgcn.splitlines() if "global_store" in line]
+        if not global_store_line:
+            return
         if cache == '' or cache == '.cg':
             assert cs_cache_modifier_str not in global_store_line[0]
             assert wt_cache_modifier_str not in global_store_line[0]