feat(go): add builtInNames set to Go language provider (#1886)

* feat(go): add builtInNames set to Go language provider

Add GO_BUILT_INS (15 functions, 18 types, 3 values) to the Go
LanguageProvider for parity with the other 13 language providers.
The set is converted to an isBuiltInName predicate by defineLanguage()
and consumed by the type-env return-type lookup to short-circuit
lookups for Go built-in symbols.

* feat(go): add Go 1.18+ and 1.21 predeclared identifiers to builtInNames

Add `clear`, `min`, `max` (Go 1.21 builtins), `any`, `comparable`
(Go 1.18 type aliases), and `iota` (predeclared constant) to
GO_BUILT_INS for complete coverage of the Go specification.

---------

Co-authored-by: Gergő Magyar <gergomagyar@icloud.com>

gitnexus/src/core/ingestion/languages/go.ts

@@ -39,6 +39,56 @@ import {
   interpretGoTypeBinding,
 } from './go/index.js';
 
+const GO_BUILT_INS: ReadonlySet<string> = new Set([
+  // built-in functions
+  'make',
+  'new',
+  'len',
+  'cap',
+  'append',
+  'copy',
+  'delete',
+  'close',
+  'panic',
+  'recover',
+  'print',
+  'println',
+  'complex',
+  'real',
+  'imag',
+  'clear',
+  'min',
+  'max',
+  // built-in types
+  'error',
+  'bool',
+  'string',
+  'int',
+  'int8',
+  'int16',
+  'int32',
+  'int64',
+  'uint',
+  'uint8',
+  'uint16',
+  'uint32',
+  'uint64',
+  'uintptr',
+  'float32',
+  'float64',
+  'complex64',
+  'complex128',
+  'byte',
+  'rune',
+  'any',
+  'comparable',
+  // built-in values
+  'true',
+  'false',
+  'nil',
+  'iota',
+]);
+
 export const goProvider = defineLanguage({
   id: SupportedLanguages.Go,
   extensions: ['.go'],
@@ -92,6 +142,7 @@ export const goProvider = defineLanguage({
   variableExtractor: createVariableExtractor(goVariableConfig),
   classExtractor: createClassExtractor(goClassConfig),
   heritageExtractor: createHeritageExtractor(goHeritageConfig),
+  builtInNames: GO_BUILT_INS,
 
   // ── RFC #909 Ring 3: scope-based resolution hooks ──────────
   emitScopeCaptures: emitGoScopeCaptures,