[LLD] Ignore ELF tests when ld.lld defaults to MinGW

Follow-up to D87418.

Differential Revision: https://reviews.llvm.org/D88991

lld/test/CMakeLists.txt

@@ -7,6 +7,7 @@ set(LLVM_LIBS_DIR "${LLVM_BINARY_DIR}/lib${LLVM_LIBDIR_SUFFIX}/%(build_config)s"
 llvm_canonicalize_cmake_booleans(
   LLVM_ENABLE_ZLIB
   LLVM_ENABLE_LIBXML2
+  LLD_DEFAULT_LD_LLD_IS_MINGW
   )
 
 configure_lit_site_cfg(

lld/test/lit.cfg.py

@@ -110,3 +110,7 @@ if tar_executable:
     sout, _ = tar_version.communicate()
     if 'GNU tar' in sout.decode():
         config.available_features.add('gnutar')
+
+# ELF tests expect the default target for ld.lld to be ELF.
+if config.ld_lld_default_mingw:
+    config.excludes.append('ELF')

lld/test/lit.site.cfg.py.in

@@ -16,6 +16,7 @@ config.python_executable = "@Python3_EXECUTABLE@"
 config.have_zlib = @LLVM_ENABLE_ZLIB@
 config.have_libxml2 = @LLVM_ENABLE_LIBXML2@
 config.sizeof_void_p = @CMAKE_SIZEOF_VOID_P@
+config.ld_lld_default_mingw = @LLD_DEFAULT_LD_LLD_IS_MINGW@
 
 # Support substitution of the tools and libs dirs with user parameters. This is
 # used when we can't determine the tool dir at configuration time.