[lldb] [test] Extend D55859 symbols.enable-external-lookup=false for more testcases

D55859 <https://reviews.llvm.org/D55859> has no effect for some of the
testcases so this patch extends it even for (all?) other testcases known to me.
LLDB was failing when LLDB prints errors reading system debug infos
(`*-debuginfo.rpm`, DWZ-optimized) which should never happen as LLDB testcases
should not be affected by system debug infos.

`lldb/packages/Python/lldbsuite/test/api/multithreaded/driver.cpp.template` is
using only SB API which does not expose `ModuleList` so I had to call
`HandleCommand()` there.

`lldb-test.cpp` could also use `HandleCommand` and then there would be no need
for `ModuleListProperties::SetEnableExternalLookup()` but I think it is cleaner
with API and not on based on text commands.

Differential Revision: https://reviews.llvm.org/D63339

llvm-svn: 363567
diff --git a/lldb/source/Core/ModuleList.cpp b/lldb/source/Core/ModuleList.cpp
index fd943d7..9d795f9 100644
--- a/lldb/source/Core/ModuleList.cpp
+++ b/lldb/source/Core/ModuleList.cpp
@@ -102,6 +102,11 @@
       nullptr, idx, g_properties[idx].default_uint_value != 0);
 }
 
+bool ModuleListProperties::SetEnableExternalLookup(bool new_value) {
+  return m_collection_sp->SetPropertyAtIndexAsBoolean(
+      nullptr, ePropertyEnableExternalLookup, new_value);
+}
+
 FileSpec ModuleListProperties::GetClangModulesCachePath() const {
   return m_collection_sp
       ->GetPropertyAtIndexAsOptionValueFileSpec(nullptr, false,