scripts: Update IREE download script to match compiler with runtime

Add early exit to skip download with runtime sha matches the installed
compiler.

Should fix the compiler mismatch when the code base hasn't synced for a
while.

Change-Id: I9b334eb2f8301442f81d59a1696236a1bc57da53

download_iree_compiler.py

diff --git a/download_iree_compiler.py b/download_iree_compiler.py
index 79cccb9..83fd678 100755
--- a/download_iree_compiler.py
+++ b/download_iree_compiler.py
@@ -5,6 +5,7 @@
 import os
 import sys
 import shutil
+import subprocess
 import tarfile
 import time
 import argparse
@@ -79,7 +80,26 @@
     )
     args = parser.parse_args()
 
+    # Check if the IREE runtime lib is in sync with the tag
+    root_dir = os.getenv("ROOTDIR")
+    cmd = ["git", "-C", f"{root_dir}/toolchain/iree", "rev-parse", "HEAD"]
+
+    try:
+        result = subprocess.run(cmd, stdout=subprocess.PIPE, check=True)
+    except subprocess.CalledProcessError as e:
+        print("Failed to check IREE runtime version")
+        sys.exit(e.returncode)
+
+    iree_runtime_commit = result.stdout.decode("utf-8")
     iree_compiler_dir = Path(args.iree_compiler_dir)
+    tag_file = iree_compiler_dir / "tag"
+
+    if os.path.isfile(tag_file):
+        with open(tag_file, "r", encoding="utf-8") as file:
+            for line in file:
+                if iree_runtime_commit.replace("\n", "") in line:
+                    print("Compiler version matches runtime. Skip download")
+                    sys.exit(0)
 
     snapshot = None
     if args.tag_name: