[core] empty synthetic class kept after method inlining

Issue details

A synthetic class whose only method gets inlined into its caller is left in the output as an empty shell:

public final /* synthetic */ class c {
}

jadx already removes empty synthetic classes (ClassModifier.isEmptySyntheticClass), but this one survives because the check runs before the inline pipeline and looks at the raw method list.

Minimal smali repro.

Trampoline.smali:

.class public final synthetic Lhusk/Trampoline;
.super Ljava/lang/Object;
.method public static synthetic bridge a(Ljava/lang/StringBuilder;)I
    .registers 1
    invoke-virtual {p0}, Ljava/lang/StringBuilder;->length()I
    move-result v0
    return v0
.end method

Caller.smali:

.class public Lhusk/Caller;
.super Ljava/lang/Object;
.method public static check(Ljava/lang/StringBuilder;)Z
    .registers 2
    invoke-static {p0}, Lhusk/Trampoline;->a(Ljava/lang/StringBuilder;)I
    move-result v0
    const/4 v1, 0x5
    if-lt v0, v1, :cond_0
    const/4 v0, 0x1
    return v0
    :cond_0
    const/4 v0, 0x0
    return v0
.end method

Caller inlines to return sb.length() >= 5;, but husk/Trampoline.java is emitted as an empty public final /* synthetic */ class Trampoline {}.

Jadx version

master (8c28a853)