GROOVY-11970: Provide support for compound assignment operator overlo…

[paulk-asert]

…ading (GEP-15)

[Copilot]

Pull request overview

Adds GEP-15 support for dedicated compound-assignment operator overloads (e.g. plusAssign) across static type checking, bytecode generation, @OperatorRename, documentation, and tests.

Changes:

• Introduces *Assign method resolution in the static type checker and propagates the resolved target to static codegen.
• Adds dynamic-mode compound-assign dispatch via ScriptBytecodeAdapter.compoundAssign and updates bytecode generation to use it.
• Documents the feature in the operator spec and adds a focused test suite for compound assignment behavior.

Reviewed changes

Copilot reviewed 13 out of 13 changed files in this pull request and generated 7 comments.

Show a summary per file

File	Description
src/test/groovy/groovy/operator/CompoundAssignmentTest.groovy	New tests covering static/dynamic *Assign selection, fallback behavior, final handling (static), setter skipping (static), and @OperatorRename scenarios.
src/spec/doc/core-operators.adoc	Documents compound assignment operator overloading and method mapping table.
src/main/java/org/codehaus/groovy/transform/stc/StaticTypesMarker.java	Adds metadata key to carry resolved *Assign target from STC into codegen.
src/main/java/org/codehaus/groovy/transform/stc/StaticTypeCheckingVisitor.java	Resolves *Assign methods for compound-assign tokens and records the chosen target; skips setter-info when in-place mutation applies.
src/main/java/org/codehaus/groovy/transform/stc/StaticTypeCheckingSupport.java	Adds token→*Assign method-name mapping helper.
src/main/java/org/codehaus/groovy/transform/OperatorRenameASTTransformation.java	Extends @OperatorRename to support *Assign renames with precedence over base operator renames.
src/main/java/org/codehaus/groovy/syntax/Types.java	Treats REMAINDER_EQUAL as an assignment operator token.
src/main/java/org/codehaus/groovy/runtime/ScriptBytecodeAdapter.java	Adds dynamic dispatcher helper for *Assign vs fallback operator call.
src/main/java/org/codehaus/groovy/classgen/asm/sc/StaticTypesBinaryExpressionMultiTypeDispatcher.java	Emits in-place *Assign calls during static compilation when STC resolved a target; maintains legacy property-set fast-path.
src/main/java/org/codehaus/groovy/classgen/asm/BinaryExpressionMultiTypeDispatcher.java	Overrides compound-assign emission to retain primitive/array fast paths.
src/main/java/org/codehaus/groovy/classgen/asm/BinaryExpressionHelper.java	Routes compound-assign tokens through new evaluateCompoundAssign helper-based path.
src/main/java/org/codehaus/groovy/classgen/Verifier.java	Skips final-variable reassignment checks for compound assigns marked as in-place via STC metadata.
src/main/java/groovy/transform/OperatorRename.java	Adds annotation members for *Assign renames.

[codecov-commenter]

Codecov Report

❌ Patch coverage is 84.72222% with 22 lines in your changes missing coverage. Please review.
✅ Project coverage is 67.2449%. Comparing base (8dde1c8) to head (0c2bb71).
⚠️ Report is 6 commits behind head on master.

Files with missing lines	Patch %	Lines
...ovy/transform/OperatorRenameASTTransformation.java	63.1579%	12 Missing and 2 partials ⚠️
...taticTypesBinaryExpressionMultiTypeDispatcher.java	88.8889%	3 Missing ⚠️
...us/groovy/classgen/asm/BinaryExpressionHelper.java	92.8571%	1 Missing and 1 partial ⚠️
...roovy/transform/stc/StaticTypeCheckingVisitor.java	91.3044%	1 Missing and 1 partial ⚠️
...codehaus/groovy/runtime/ScriptBytecodeAdapter.java	83.3333%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@                Coverage Diff                 @@
##               master      #2499        +/-   ##
==================================================
+ Coverage     67.2264%   67.2449%   +0.0185%     
- Complexity      31984      32016        +32     
==================================================
  Files            1468       1468                
  Lines          123923     124054       +131     
  Branches        22251      22266        +15     
==================================================
+ Hits            83309      83420       +111     
- Misses          33433      33452        +19     
- Partials         7181       7182         +1     

Files with missing lines	Coverage Δ
...in/java/org/codehaus/groovy/classgen/Verifier.java	90.0938% <100.0000%> (+0.0207%)	⬆️
...ssgen/asm/BinaryExpressionMultiTypeDispatcher.java	86.9347% <100.0000%> (-1.7833%)	⬇️
...rc/main/java/org/codehaus/groovy/syntax/Types.java	74.0458% <ø> (ø)
...roovy/transform/stc/StaticTypeCheckingSupport.java	82.0292% <100.0000%> (+0.2190%)	⬆️
...dehaus/groovy/transform/stc/StaticTypesMarker.java	100.0000% <100.0000%> (ø)
...codehaus/groovy/runtime/ScriptBytecodeAdapter.java	65.4762% <83.3333%> (+0.2588%)	⬆️
...us/groovy/classgen/asm/BinaryExpressionHelper.java	88.8179% <92.8571%> (-1.1985%)	⬇️
...roovy/transform/stc/StaticTypeCheckingVisitor.java	87.5000% <91.3044%> (+0.0230%)	⬆️
...taticTypesBinaryExpressionMultiTypeDispatcher.java	86.9565% <88.8889%> (+0.1918%)	⬆️
...ovy/transform/OperatorRenameASTTransformation.java	64.3564% <63.1579%> (+3.4189%)	⬆️

... and 6 files with indirect coverage changes

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