moved SkSL InterfaceBlock data into IRNode

Change-Id: If85369d978e395502b2169d605c2513a9086b57e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/326916
Commit-Queue: Ethan Nicholas <ethannicholas@google.com>
Reviewed-by: John Stiles <johnstiles@google.com>
diff --git a/src/sksl/SkSLCompiler.cpp b/src/sksl/SkSLCompiler.cpp
index 9784f83..5c9f602 100644
--- a/src/sksl/SkSLCompiler.cpp
+++ b/src/sksl/SkSLCompiler.cpp
@@ -378,9 +378,9 @@
                 break;
             }
             case ProgramElement::Kind::kInterfaceBlock: {
-                const Variable* var = element->as<InterfaceBlock>().fVariable;
-                SkASSERT(var->isBuiltin());
-                intrinsics->insertOrDie(var->name(), std::move(element));
+                const Variable& var = element->as<InterfaceBlock>().variable();
+                SkASSERT(var.isBuiltin());
+                intrinsics->insertOrDie(var.name(), std::move(element));
                 break;
             }
             default: