test: fill coverage gaps in `languages/java`

[KRRT7]

Parent: #2079

Phase 3 — languages/java to 100%

Module	Stmts	Current coverage
languages/java	7,467	73%

Key files needing attention:

• java/gradle_strategy.py (569 stmts, 33%)
• java/function_optimizer.py (228 stmts, 43%)
• java/maven_strategy.py (623 stmts, 52%)
• java/line_profiler.py (220 stmts, 58%)
• java/test_runner.py (807 stmts, 59%)
• java/support.py (282 stmts, 64%)
• java/formatter.py (143 stmts, 64%)
• java/comparator.py (172 stmts, 70%)
• java/parse.py (133 stmts, 69%)
• java/jfr_parser.py (145 stmts, 74%)
• java/replacement.py (415 stmts, 78%)
• java/tracer.py (98 stmts, 82%)
• java/instrumentation.py (624 stmts, 84%)
• java/context.py (469 stmts, 85%)

Target

100% coverage for languages/java (~7,467 statements).