Arm backend: aot_arm_compiler.py support budleio output without a path

BundleIO output generation needed a the output file to exist in a
folder, so if you wanted to output a file in the current folder you
neeed to add "./" in front of the file name like "./file.bpte" this
fixes this problem, normal .pte already support this.

Signed-off-by: Zingo Andersen <Zingo.Andersen@arm.com>
Change-Id: I8cb941cc068383619a51aaf79e88b59b7e4ad901

Author: zingo

backends/arm/scripts/aot_arm_compiler.py

@@ -778,7 +778,8 @@ def _save_bpte_program(
 
     # Generate BundledProgram
     output_dir = os.path.dirname(output_name)
-    os.makedirs(output_dir, exist_ok=True)
+    if output_dir:
+        os.makedirs(output_dir, exist_ok=True)
     _save_bundled_program(exec_prog, method_test_suites, output_name)