[LLDB] Filter out -Werror options when setting up -cc1 Clang Invocations

The non-caching code path was already doing this, but the code path
for cc1 flags was missing this functionality. Even though LLDB is
replaying the compile-time compiler invocation, we have seen reports
where additional warnings get diagnosed at debug time, effectively
rendering the debug session unusable.

rdar://174422552

Author: adrian-prantl

lldb/source/Plugins/TypeSystem/Swift/SwiftASTContext.cpp

@@ -2014,7 +2014,8 @@ void SwiftASTContext::AddExtraClangCC1Args(
     // Workaround for the extra driver argument embedded in the swiftmodule by
     // some swift compiler version. It always starts with `--target=` and it is
     // not a valid cc1 option.
-    if (!StringRef(Arg).starts_with("--target="))
+    if (!StringRef(Arg).starts_with("--target=") &&
+        !StringRef(Arg).starts_with("-Werror"))
       clangArgs.push_back(Arg.c_str());
   });
   // Append some search paths from swift invocation so lldb can import

lldb/test/API/lang/swift/clangimporter/caching/Makefile

@@ -1,6 +1,6 @@
 SWIFT_SOURCES := main.swift
 SWIFT_ENABLE_EXPLICIT_MODULES := YES
-SWIFTFLAGS_EXTRAS = -I$(SRCDIR) -I/TEST_DIR -F/FRAMEWORK_DIR -cache-compile-job -cas-path $(BUILDDIR)/cas
+SWIFTFLAGS_EXTRAS = -I$(SRCDIR) -I/TEST_DIR -F/FRAMEWORK_DIR -cache-compile-job -cas-path $(BUILDDIR)/cas -Xcc -Werror
 
 all: a.out cas-config
 

lldb/test/API/lang/swift/clangimporter/caching/TestSwiftClangImporterCaching.py

@@ -34,5 +34,6 @@ def test(self):
 #       CHECK:  SwiftASTContextForExpressions(module: "a", cu: "main.swift")::LogConfiguration() --     -DADDED=1
 #       CHECK:  SwiftASTContextForExpressions(module: "a", cu: "main.swift")::LogConfiguration() --     -DEXTRA=1
 #       CHECK:  SwiftASTContextForExpressions(module: "a", cu: "main.swift") Module import remark: loaded module 'ClangA'
+#       CHECK-NOT: -Werror
 #       CHECK-NOT: -cc1
 #       CHECK-NOT: Clang error