runtime: clean code, impl reflect arrayOf, chanOf, structOf

[visualfc]

• ssa/abi: abi types.Named check scope indices
  ( Name.N.N... N is scope in parent scope index. eg: func demo() { type T int } T => T.1.0 )
• ssa/abi: fix abi types.Named str pkgpath.name => pkgname.name
• ssa: fix abi struct pkgpath by field
• ssa: fix abi closure funcType
• reflect: impl ArrayOf, ChanOf, StructOf
• runtime: clean type func

[gemini-code-assist]

Summary of Changes

Hello @visualfc, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request focuses on a significant code cleanup and refactoring effort within the Go runtime's internal reflection mechanisms. The primary objective is to enhance code organization by relocating numerous type-related utility functions and constants to a more semantically appropriate file, z_type.go, from z_face.go. This change also includes a simplification of the logic for retrieving type names in type.go, contributing to a more streamlined and maintainable codebase for runtime type handling.

Highlights

• Code Refactoring: Moved several type-related constants and utility functions, such as hdrSizeOf, NewNamed, Func, funcStr, hashTuple, and shallowHash, from runtime/internal/runtime/z_face.go to runtime/internal/runtime/z_type.go to centralize type-related logic.
• API Simplification: Simplified the Name() method in runtime/internal/lib/reflect/type.go by removing special conditional handling for basic types, leading to a more direct and cleaner implementation.
• Consolidation of Type Utilities: Consolidated various functions responsible for type creation, string representation, and hashing into runtime/internal/runtime/z_type.go, improving modularity and maintainability within the runtime package.

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[gemini-code-assist]

Code Review

This pull request provides a good cleanup of the runtime code by refactoring several type-related functions into a more appropriate file (z_type.go) and removing what appears to be a significant amount of unused code. These changes improve the overall code structure and maintainability. However, I've identified one critical regression in reflect/type.go where a simplification to the Name() method will cause it to behave incorrectly for basic types. Please see the specific comment for details.

[xgopilot]

Code Review Summary

This PR performs a clean refactoring by reorganizing type-related functions from z_face.go to z_type.go and removing dead code. The file organization improvement is excellent, separating interface operations from type construction.

Overall Assessment: One critical issue found that needs attention.

---

✅ Strengths

• Excellent code organization: Functions are now logically grouped by purpose
• Safe dead code removal: All removed functions have zero references in the codebase
• No performance impact: Code movement is performance-neutral
• No security issues: All unsafe operations remain properly guarded
• Clean refactoring: No breaking changes to public APIs

---

⚠️ Critical Issue: Removed Basic Type Handling

The removal of special case handling for basic types in reflect.Name() appears problematic. The original code handled basic types (int, string, bool, etc.) which don't have TFlagNamed set but do have names.

Impact: The current implementation returns empty string for basic types instead of their names (e.g., "int", "string").

Recommendation: Either restore the original logic or add documentation explaining why this behavior change is intentional.

See inline comment for details.

[codecov]

Codecov Report

❌ Patch coverage is 97.29730% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 91.04%. Comparing base (c844c73) to head (efb546d).
⚠️ Report is 9 commits behind head on main.

Files with missing lines	Patch %	Lines
ssa/abi/abi.go	94.11%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1515      +/-   ##
==========================================
+ Coverage   90.78%   91.04%   +0.26%     
==========================================
  Files          45       45              
  Lines       11970    11996      +26     
==========================================
+ Hits        10867    10922      +55     
+ Misses        929      897      -32     
- Partials      174      177       +3     

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[xgopilot]

Code Review Summary

This PR implements significant refactoring of the runtime reflection system, adding ArrayOf, ChanOf, and StructOf functions. The code demonstrates solid engineering with appropriate defensive checks and caching strategies.

Critical Issue:

• emitGCMask function is completely disabled (line 1571) but is called for GC mask generation. This needs immediate attention.

Key Concerns:

• Integer overflow checks should occur before arithmetic operations (lines 1618, 1933)
• Significant code duplication in embedded field method handling (lines 1831-1911)
• Documentation inaccuracies in StructOf panic conditions

Positive Aspects:

• Good use of caching to avoid duplicate type creation
• Comprehensive input validation with appropriate panics
• Proper concurrent access patterns with double-checked locking

Please address the critical emitGCMask issue before merging.