[lldb][ClangExpression] Fix LLDB_LOG incorrect format specifier

[Michael137]

Summary

Previously this would log:

 FindExternalLexicalDecls on (ASTContext*)0x00000005CE825200 'Expression
ASTContext for '<user expression 0>'' in 'weak_ptr'
(%sDecl*)ClassTemplateSpecialization
 FindExternalLexicalDecls on (ASTContext*)0x00000005CE825200 'Expression
ASTContext for '<user expression 0>'' in '__shared_count'
(%sDecl*)CXXRecord

Note that the %s isn't actually respected. This patch fixes this
by providing the format specifiers that lldb::formatv supports.

[JDevlieghere]

LGTM

lldb/source/Plugins/ExpressionParser/Clang/ClangASTSource.cpp

if (iter != m_active_lexical_decls.end())
     return;
   m_active_lexical_decls.insert(context_decl);
   ScopedLexicalDeclEraser eraser(m_active_lexical_decls, context_decl);
 
   if (log) {
     if (const NamedDecl *context_named_decl = dyn_cast<NamedDecl>(context_decl))
       LLDB_LOG(log,
                "FindExternalLexicalDecls on (ASTContext*){0} '{1}' in "
-               "'{2}' (%sDecl*){3}",
+               "'{2}' ({3}Decl*){4}",
                m_ast_context, m_clang_ast_context->getDisplayName(),
                context_named_decl->getNameAsString().c_str(),
                context_decl->getDeclKindName(),
                static_cast<const void *>(context_decl));
     else if (context_decl)
       LLDB_LOG(log,
                "FindExternalLexicalDecls on (ASTContext*){0} '{1}' in "
                "({2}Decl*){3}",