Fix VerifyError when using class-inject with -Xverify:all

[mcculls]

What Does This Do

The originalError local was stored as the first instruction inside the try range that protects it, so the verifier's async-exception frame at the handler couldn't assume it was initialized, causing a VerifyError on JVMs that verify bootstrap-loader-defined classes (e.g. -Xverify:all). Move the try range to start after the store instead.

Motivation

Fixes:

java.lang.UnsupportedOperationException
  at datadog.instrument.classinject.ClassInjector.enableClassInjection(ClassInjector.java:141)
  at datadog.trace.bootstrap.Agent.start(Agent.java:226)
  at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
  at java.base/java.lang.reflect.Method.invoke(Method.java:580)
  at datadog.trace.bootstrap.AgentBootstrap.agentmainImpl(AgentBootstrap.java:166)
  at datadog.trace.bootstrap.AgentBootstrap.agentmain(AgentBootstrap.java:73)
  at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
  at java.base/java.lang.reflect.Method.invoke(Method.java:580)
  at datadog.trace.bootstrap.AgentPreCheck.continueBootstrap(AgentPreCheck.java:172)
  at datadog.trace.bootstrap.AgentPreCheck.agentmain(AgentPreCheck.java:27)
  at datadog.trace.bootstrap.AgentPreCheck.premain(AgentPreCheck.java:20)
  at java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke(DirectMethodHandleAccessor.java:103)
  at java.base/java.lang.reflect.Method.invoke(Method.java:580)
  at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndStartAgent(InstrumentationImpl.java:560)
  at java.instrument/sun.instrument.InstrumentationImpl.loadClassAndCallPremain(InstrumentationImpl.java:572)
Caused by: java.lang.VerifyError
  at java.base/java.lang.ClassLoader.defineClass0(Native Method)
  at java.base/java.lang.System$2.defineClass(System.java:2395)
  at java.base/java.lang.invoke.MethodHandles$Lookup$ClassDefiner.defineClass(MethodHandles.java:2505)
  at java.base/java.lang.invoke.MethodHandles$Lookup$ClassDefiner.defineClassAsLookup(MethodHandles.java:2484)
  at java.base/java.lang.invoke.MethodHandles$Lookup.defineHiddenClass(MethodHandles.java:2150)
  at java.base/java.lang.Class.forName(Unknown Source)
  at datadog.instrument.classinject.ClassInjector.injectViaForName(ClassInjector.java:179)
  at datadog.instrument.classinject.ClassInjector.enableClassInjection(ClassInjector.java:139)
  ... 14 more

On systems with strict class verification turned on for all classes, such as -Xverify:all

Note when this fails the downstream agent falls back to a different approach, so there's no actual impact on the application - but this fix will stop it from having to do that fall back on those few deployments with full verification enabled.

Contributor Checklist

Jira ticket: [PROJ-IDENT]

[ygree]

Nice fix!