add initializer to LinkCompletionTools.SymbolInformation that accepts a SymbolGraph.Symbol (#1253)

Author: matthewbastien

Sources/SwiftDocC/DocumentationService/Convert/Symbol Link Resolution/LinkCompletionTools.swift

@@ -9,6 +9,7 @@
 */
 
 import Foundation
+public import SymbolKit
 
 /// A collection of API for link completion.
 ///
@@ -184,6 +185,15 @@ public enum LinkCompletionTools {
             self.parameterTypes = parameterTypes
             self.returnTypes = returnTypes
         }
+
+        public init(symbol: SymbolGraph.Symbol) {
+            self.kind = symbol.kind.identifier.identifier
+            self.symbolIDHash = Self.hash(uniqueSymbolID: symbol.identifier.precise)
+            if let signature = PathHierarchy.functionSignatureTypeNames(for: symbol) {
+                self.parameterTypes = signature.parameterTypeNames
+                self.returnTypes = signature.returnTypeNames
+            }
+        }
 
         /// Creates a hashed representation of a symbol's unique identifier.
         ///