[llvm-jitlink] [test] Add an XFAIL for a JITLink test on MinGW

This testcase fails on MinGW targets, because when compiling the
main() function, it gets an implicit call to __main(), which is
missing in this context.

Author: mstorsjo

llvm/test/ExecutionEngine/JITLink/Generic/sectcreate.test

@@ -8,4 +8,9 @@
 # Jitlink does not support ARM64 COFF files.
 # UNSUPPORTED: target=aarch64-pc-windows-{{.*}}
 
+# On MinGW targets, when compiling the main() function, it gets
+# an implicitly generated call to __main(), which is missing in
+# this context.
+# XFAIL: target={{.*}}-windows-gnu
+
 # jitlink-check: *{4}foo = 0x2a2a5a5a