Par back sourceSymbol usage, to keep some non-source

Given:

    class Foo(name: String, age: Int)
    case class Person(name: String)

Is the Foo constructor symbol synthetic?  Being the primary
constructor, sourceSymbol considers it should be substituted for the Foo
class symbol.

Similarly, the Person apply method symbol is replaced by the class
symbol for Person (via the Person module class).

Doing so leads the presentation compiler to show details about the
class, rather than the constructor or the apply method intially
targeted.

[Cherry-picked 6792fc7]

Author: dwijnand

compiler/src/dotty/tools/dotc/core/Symbols.scala

@@ -305,7 +305,7 @@ object Symbols extends SymUtils {
 
     /** A symbol related to `sym` that is defined in source code.
      *
-     *  @see enclosingSourceSymbols
+     *  @see [[interactive.Interactive.enclosingSourceSymbols]]
      */
     @annotation.tailrec final def sourceSymbol(using Context): Symbol =
       if (!denot.exists)

presentation-compiler/src/main/dotty/tools/pc/MetalsInteractive.scala

@@ -229,7 +229,14 @@ object MetalsInteractive:
         end if
       case Nil => Nil
     end go
-    go(path).map((sym, tp) => (sym.sourceSymbol, tp))
+    go(path).map { (sym, tp) =>
+      if sym.is(Synthetic) && sym.name == StdNames.nme.apply then
+        (sym, tp) // return synthetic apply, rather than the apply's owner
+      else if sym.isClassConstructor && sym.isPrimaryConstructor then
+        (sym, tp) // return the class constructor, rather than the class (so skip trait constructors)
+      else
+        (sym.sourceSymbol, tp)
+    }
   end enclosingSymbolsWithExpressionType
 
   import dotty.tools.pc.utils.MtagsEnrichments.*