Reapply #2 [clang-repl] [test] Make an XFAIL more precise (llvm#71168)

The const.cpp testcase fails when running in MSVC mode, while it does
succeed in MinGW mode.

In MSVC mode, there are more constructor invocations than expected, as
the printout looks like this:

    A(1), this = 0000025597930000
    A(1), this = 0000025597930000
    f: this = 0000025597930000, val = 1
    A(1), this = 0000025597930000
    f: this = 0000025597930000, val = 1
    ~A, this = 0000025597930000, val = 1
    ~A, this = 0000025597930000, val = 1
    ~A, this = 0000025597930000, val = 1

While the expected printout looks like this:

    A(1), this = 000002C903E10000
    f: this = 000002C903E10000, val = 1
    f: this = 000002C903E10000, val = 1
    ~A, this = 000002C903E10000, val = 1

Reapplying llvm#70991 with the XFAIL changed to check the host triple, not
the target triple. On an MSVC based build of Clang, but with the default
target triple set to PS4/PS5, we will still see the failure. And a Linux
based build of Clang that targets PS4/PS5 won't see the issue.

Author: mstorsjo

clang/test/Interpreter/const.cpp

@@ -1,6 +1,6 @@
 // UNSUPPORTED: system-aix
 // see https://github.com/llvm/llvm-project/issues/68092
-// XFAIL: system-windows
+// XFAIL: host={{.*}}-windows-msvc
 
 // RUN: cat %s | clang-repl | FileCheck %s
 // RUN: cat %s | clang-repl -Xcc -O2 | FileCheck %s

llvm/test/lit.cfg.py

@@ -477,10 +477,6 @@ def have_cxx_shared_library():
     if not config.target_triple.startswith(("nvptx", "xcore")):
         config.available_features.add("object-emission")
 
-# Allow checking for specific details in the host triple
-if config.host_triple:
-    config.available_features.add('host=%s' % config.host_triple)
-
 if config.have_llvm_driver:
     config.available_features.add("llvm-driver")
 

llvm/utils/lit/lit/llvm/config.py

@@ -97,6 +97,7 @@ def __init__(self, lit_config, config):
         # part of the standard header.  But currently they aren't)
         host_triple = getattr(config, "host_triple", None)
         target_triple = getattr(config, "target_triple", None)
+        features.add("host=%s" % host_triple)
         features.add("target=%s" % target_triple)
         if host_triple and host_triple == target_triple:
             features.add("native")