fixed jvm/bin/java check for windows in mx_graalpython.graalpy_standalone_home()

Author: tomasstupka

mx.graalpython/mx_graalpython.py

@@ -764,7 +764,7 @@ def graalpy_standalone_home(standalone_type, enterprise=False, dev=False, build=
         python_home = os.path.abspath(glob.glob(python_home)[0])
         mx.log("Using GraalPy standalone from GRAALPY_HOME: " + python_home)
         # Try to verify that we're getting what we expect:
-        has_java = os.path.exists(os.path.join(python_home, 'jvm', 'bin', 'java'))
+        has_java = os.path.exists(os.path.join(python_home, 'jvm', 'bin', 'java.exe' if WIN32 else 'java'))
         if has_java != (standalone_type == 'jvm'):
             mx.abort(f"GRAALPY_HOME is not compatible with the requested distribution type.\n"
                      f"jvm/bin/java exists?: {has_java}, requested type={standalone_type}.")