Play Framework

perf(boot): create the Java compiler on first use, not at every start

ApplicationClasses built its ApplicationCompiler in a field initialiser,
so Play.init loaded that class in every start. Verifying it resolves the
JDT interfaces it mentions, and those come out of a signed jar: about
50 ms of a precompiled start went to a compiler such a start never
runs, in the part of the "Started in" line no phase accounts for.

The compiler is now created when something is first compiled. A start
that compiles, in DEV or in PROD without precompiled classes, pays the
same cost as before, at its first compilation. java.source is checked
at that point too, so a precompiled application no longer reads it.

Guarded by a precompiled boot under -Xlog:class+load that must load no
org.eclipse.jdt class.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01KDUoh3KhBpfjXn4rV6H356