[WASM] Fix reading non-utf8 file contents

Author: kateinoigakukun

test/lit.cfg

@@ -1391,11 +1391,17 @@ elif run_os == 'wasi':
     # Exclude test cases that use objc-interop because clang doesn't support it
     # with WebAssembly binary file yet.
     def use_objc_interop(path):
-      with open(path) as f:
-        return '-enable-objc-interop' in f.read()
+      try:
+        with open(path) as f:
+          return '-enable-objc-interop' in f.read()
+      except:
+        return False
     def lldb_related_test(path):
-      with open(path) as f:
-        return 'lldb-moduleimport-test' in f.read()
+      try:
+        with open(path) as f:
+          return 'lldb-moduleimport-test' in f.read()
+      except:
+        return False
 
     def disabled_filenames(path):
       matches = []