Fix variable resolution of object body params (#1788)

Fixes a regression introduced in Pkl 0.32.

pkl-core/src/main/java/org/pkl/core/ast/builder/SymbolTable.java

@@ -523,6 +523,13 @@ public final class SymbolTable {
         if (scope instanceof LexicalScope lex) {
           if (shouldSkip && !(scope instanceof ForGeneratorScope)) {
             if (scope instanceof ObjectScope objectScope && objectScope.hasParams()) {
+              // skipping the object scope should now see the object body params, because the params
+              // are one level higher than the body itself.
+              var result = fun.apply(objectScope, levelsUp);
+              if (result instanceof Parameter parameter) {
+                //noinspection unchecked
+                return (R) new Parameter(parameter.slot(), parameter.levelsUp() - 1);
+              }
               levelsUp++;
             }
             // An EagerGeneratorScope (for `when` predicates) skipped an ObjectScope.

pkl-core/src/test/files/LanguageSnippetTests/input/generators/forGeneratorObjectBodyParam.pkl

@@ -0,0 +1,9 @@
+foo = new Mapping {
+  default { key ->
+    for (idx, char in key.split("")) {
+      ["\(char)_\(idx)"] = "hi"
+    }
+  }
+  ["zzz"] {}
+}
+

pkl-core/src/test/files/LanguageSnippetTests/input/generators/whenGeneratorObjectBodyParam.pkl

@@ -0,0 +1,8 @@
+foo = new Mapping {
+  default { key ->
+    when (key is String) {
+      bar = key
+    }
+  }
+  ["x"] {}
+}

pkl-core/src/test/files/LanguageSnippetTests/output/generators/forGeneratorObjectBodyParam.pcf

@@ -0,0 +1,7 @@
+foo {
+  ["zzz"] {
+    ["z_0"] = "hi"
+    ["z_1"] = "hi"
+    ["z_2"] = "hi"
+  }
+}

pkl-core/src/test/files/LanguageSnippetTests/output/generators/whenGeneratorObjectBodyParam.pcf

@@ -0,0 +1,5 @@
+foo {
+  ["x"] {
+    bar = "x"
+  }
+}