[llvm][Support] Only enable backtrace test when it's enabled

rdar://138554797

Author: jroelofs

llvm/test/CMakeLists.txt

@@ -1,6 +1,7 @@
 llvm_canonicalize_cmake_booleans(
   BUILD_SHARED_LIBS
   HAVE_OCAMLOPT
+  LLVM_ENABLE_BACKTRACES
   LLVM_ENABLE_DIA_SDK
   LLVM_ENABLE_FFI
   LLVM_ENABLE_THREADS

llvm/test/Other/crash-stack-trace.ll

@@ -1,4 +1,4 @@
-; REQUIRES: asserts
+; REQUIRES: asserts, backtrace-enabled
 
 ; RUN: not --crash opt -passes=trigger-crash-module %s -disable-output 2>&1 | \
 ; RUN: FileCheck %s --check-prefix=CHECK-MODULE

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

@@ -41,6 +41,7 @@ config.have_httplib = @LLVM_ENABLE_HTTPLIB@
 config.have_dia_sdk = @LLVM_ENABLE_DIA_SDK@
 config.enable_ffi = @LLVM_ENABLE_FFI@
 config.build_examples = @LLVM_BUILD_EXAMPLES@
+config.enable_backtrace = @LLVM_ENABLE_BACKTRACES@
 config.enable_threads = @LLVM_ENABLE_THREADS@
 config.build_shared_libs = @BUILD_SHARED_LIBS@
 config.link_llvm_dylib = @LLVM_LINK_LLVM_DYLIB@
@@ -65,6 +66,9 @@ config.have_vc_rev = @LLVM_APPEND_VC_REV@
 config.force_vc_rev = "@LLVM_FORCE_VC_REVISION@"
 config.has_logf128 = @LLVM_HAS_LOGF128@
 
+if config.enable_backtrace:
+    config.available_features.add('backtrace-enabled')
+
 import lit.llvm
 lit.llvm.initialize(lit_config, config)