Remove source location workaround for autoclosures.

This patch reverts a workaround that was put into pre-1.0 Swift to
avoid linetable entries for autoclosure functions. Nowadays
autoclosures aren't emitted in separate functions, which makes this
obsolete. The workaround also was no longer being tested by the test
suite.

rdar://89776340

Author: adrian-prantl

lib/SIL/IR/SILLocation.cpp

@@ -79,17 +79,6 @@ SourceLoc SILLocation::getSourceLocForDebugging() const {
   if (isSILFile())
     return storage.sourceLoc;
 
-  if (auto *expr = getPrimaryASTNode().dyn_cast<Expr*>()) {
-    // Code that has an autoclosure as location should not show up in
-    // the line table (rdar://problem/14627460). Note also that the
-    // closure function still has a valid DW_AT_decl_line.  Depending
-    // on how we decide to resolve rdar://problem/14627460, we may
-    // want to use the regular getLoc instead and rather use the
-    // column info.
-    if (isa<AutoClosureExpr>(expr))
-      return SourceLoc();
-  }
-
   if (hasASTNodeForDebugging())
     return getSourceLoc(storage.extendedASTNodeLoc->forDebugging);