[lldb][test] XFAIL TestAnonNamespaceParamFunc.cpp on Windows

This recently added test is failing on Windows with:
```
c:\users\tcwg\llvm-worker\lldb-aarch64-windows\build\bin\lldb.exe --no-lldbinit -S C:/Users/tcwg/llvm-worker/lldb-aarch64-windows/build/tools/lldb\test\Shell\lit-lldb-init-quiet C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\build\tools\lldb\test\Shell\Expr\Output\TestAnonNamespaceParamFunc.cpp.tmp -o run -o "expression func(a)" -o exit | c:\users\tcwg\llvm-worker\lldb-aarch64-windows\build\bin\filecheck.exe C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\llvm-project\lldb\test\Shell\Expr\TestAnonNamespaceParamFunc.cpp
executed command: 'c:\users\tcwg\llvm-worker\lldb-aarch64-windows\build\bin\lldb.exe' --no-lldbinit -S 'C:/Users/tcwg/llvm-worker/lldb-aarch64-windows/build/tools/lldb\test\Shell\lit-lldb-init-quiet' 'C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\build\tools\lldb\test\Shell\Expr\Output\TestAnonNamespaceParamFunc.cpp.tmp' -o run -o 'expression func(a)' -o exit
.---command stderr------------
| TestAnonNamespaceParamFunc.cpp.tmp :: Class 'tagARRAYDESC' has a member 'tdescElem' of type 'tagTYPEDESC' which does not have a complete definition.error: TestAnonNamespaceParamFunc.cpp.tmp :: Class 'tagARRAYDESC' has a member 'tdescElem' of type 'tagTYPEDESC' which does not have a complete definition.
| (lldb) TestAnonNamespaceParamFunc.cpp.tmp :: Class 'std::partial_ordering' has a member 'less' of type 'std::partial_ordering' which does not have a complete definition.error: TestAnonNamespaceParamFunc.cpp.tmp :: Class 'std::partial_ordering' has a member 'less' of type 'std::partial_ordering' which does not have a complete definition.
| (lldb) TestAnonNamespaceParamFunc.cpp.tmp :: Class 'std::strong_ordering' has a member 'less' of type 'std::strong_ordering' which does not have a complete definition.error: TestAnonNamespaceParamFunc.cpp.tmp :: Class 'std::strong_ordering' has a member 'less' of type 'std::strong_ordering' which does not have a complete definition.
| (lldb) TestAnonNamespaceParamFunc.cpp.tmp :: Class 'std::weak_ordering' has a member 'less' of type 'std::weak_ordering' which does not have a complete definition.error: TestAnonNamespaceParamFunc.cpp.tmp :: Class 'std::weak_ordering' has a member 'less' of type 'std::weak_ordering' which does not have a complete definition.
| (lldb) error: Couldn't look up symbols:
|   int func(struct `anonymous namespace'::InAnon)
| Hint: The expression tried to call a function that is not present in the target, perhaps because it was optimized out by the compiler.
`-----------------------------
executed command: 'c:\users\tcwg\llvm-worker\lldb-aarch64-windows\build\bin\filecheck.exe' 'C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\llvm-project\lldb\test\Shell\Expr\TestAnonNamespaceParamFunc.cpp'
.---command stderr------------
| C:\Users\tcwg\llvm-worker\lldb-aarch64-windows\llvm-project\lldb\test\Shell\Expr\TestAnonNamespaceParamFunc.cpp:10:11: error: CHECK: expected string not found in input
| // CHECK: (int) $0 = 15
|           ^
| <stdin>:16:26: note: scanning from here
| (lldb) expression func(a)
|                          ^
```

So the function is still not callable. But AFAICT, this is not a
regression, since this function wasn't callable prior to the patch
anyway. I currently do not have a Windows setup to test this on,
so XFAIL for now.

lldb/test/Shell/Expr/TestAnonNamespaceParamFunc.cpp

@@ -3,6 +3,8 @@
 // linkage. In this case, a function whose argument
 // is not legally usable outside this TU.
 
+// XFAIL: system-windows
+
 // RUN: %build %s -o %t
 // RUN: %lldb %t -o run -o "expression func(a)" -o exit | FileCheck %s