AA: do not use full decompilation for built-ins

This is the major performance bottleneck for AA/UAST artifacts rollout
to Android Lint. KT stubs are good/fast enough.

analysis/analysis-api/testData/standalone/singleModule/listIterator.txt

@@ -1,2 +1,2 @@
 Resolved to:
-public abstract fun add(element: T): kotlin.Unit
+KtNamedFunction:add(element)

analysis/analysis-api/testData/standalone/singleModule/mapGetOrDefault.txt

@@ -1,2 +1,2 @@
 Resolved to:
-@kotlin.SinceKotlin @kotlin.internal.PlatformDependent public open fun getOrDefault(key: K, defaultValue: V): V { /* compiled code */ }
+KtNamedFunction:getOrDefault(key, defaultValue)