limit symbol basename-ification to Swift/C/C++/ObjC++ or unknown lang…

…uage

This change allows commands like:
    breakpoint set -n main.main
and
    breakpoint set -n main.init

to work in Go if either:
(1) a -L language specifier is given (i.e. appending "-L go" to the
    above lines), or
(2) setting the default language via:
    (lldb) settings set target.language go

This addresses some usability issues around investigating:
https://bugs.swift.org/browse/SR-527

source/Core/Module.cpp

@@ -1780,9 +1780,15 @@ Module::PrepareForFunctionNameLookup (const ConstString &name,
             CPlusPlusLanguage::MethodName cpp_method (name);
             SwiftLanguageRuntime::MethodName swift_method (name, true);
 
-            if (swift_method.IsValid())
+            if ((language == eLanguageTypeUnknown ||
+                 language == eLanguageTypeSwift) &&
+                swift_method.IsValid())
                 basename = swift_method.GetBasename();
-            else if (cpp_method.IsValid())
+            else if ((language == eLanguageTypeUnknown ||
+                      Language::LanguageIsCPlusPlus(language) ||
+                      Language::LanguageIsC(language) ||
+                      language == eLanguageTypeObjC_plus_plus) &&
+                     cpp_method.IsValid())
                 basename = cpp_method.GetBasename();
 
             if (basename.empty())