[NFC] Replace `compare` with (in)equality operator where applicable.

Using compare is verbose, bug prone and potentially inefficient (because
of early termination). Replace relevant call sites with the (in)equality
operator.

llvm-svn: 349972
diff --git a/lldb/source/Symbol/ClangASTContext.cpp b/lldb/source/Symbol/ClangASTContext.cpp
index 0fb4699..5052f3c 100644
--- a/lldb/source/Symbol/ClangASTContext.cpp
+++ b/lldb/source/Symbol/ClangASTContext.cpp
@@ -7452,7 +7452,7 @@
                                                base_class->getType());
             std::string base_class_type_name(
                 base_class_clang_type.GetTypeName().AsCString(""));
-            if (base_class_type_name.compare(name) == 0)
+            if (base_class_type_name == name)
               return child_idx;
             ++child_idx;
           }