Constructor signature not remapped

[Johni0702]

Or more generally, when there is no explicit MethodMapping for a method, any AT for that method will not have its descriptor remapped, even though the descriptor may contain types which do have mappings.
E.g. remapping from srg to official names:

# Input
public net.minecraft.client.resources.ResourcePackRepository$Entry <init>(Lnet/minecraft/client/resources/ResourcePackRepository;Ljava/io/File;)V # constructor
# Expected
public bnm$a <init>(Lbnm;Ljava/io/File;)V
# Actual
public bnm$a <init>(Lnet/minecraft/client/resources/ResourcePackRepository;Ljava/io/File;)V