[Bug]: Debugger fails to list and evaluate `binding-pattern` variables

[lochana-chathura]

Description

$subject.

• As you can observe in the following screenshot, binding pattern variables name, index1, postType, negType are not listed under the local variables on the left window.

• Also notice, variables that are listed already; pos, neg, and d, only the name is showing. Cannot expand those values and see what's inside.

• typing variables in the evaluator also fails.

Steps to Reproduce

1. checkout to this commit (https://github.com/ballerina-platform/nballerina/commit/9c70a7cf23d11d2fc568a56ef04a709eefc51456) in nballerina repo. Currently, it is the latest commit.
2. Apply the following small patch to run only the record-t.bal test file.

   diff --git a/compiler/tests/testSuite.bal b/compiler/tests/testSuite.bal
   index 73a088aa..7468a12b 100644
   --- a/compiler/tests/testSuite.bal
   +++ b/compiler/tests/testSuite.bal
   @@ -154,6 +154,9 @@ function listSources(string initialChars) returns TestSuiteCases|io:Error|file:E
            if ext != ".bal" {
                continue;
            }
   +            if base != "record-t" {
   +                continue;
   +            }
            int? dash = base.lastIndexOf("-");
            test:assertTrue(dash is int, "test file name must be in <name>-<kind>.bal format");
            string testKind = base.substring(1 + <int>dash);

3. Add a debugging point at the following line. https://github.com/ballerina-platform/nballerina/blob/9c70a7cf23d11d2fc568a56ef04a709eefc51456/compiler/modules/types/mapping.bal#L166
4. Run the following test in debugger mode. https://github.com/ballerina-platform/nballerina/blob/9c70a7cf23d11d2fc568a56ef04a709eefc51456/compiler/tests/testSuite.bal#L38

Affected Version(s)

2201.8.5 at least

OS, DB, other environment details and versions

MacOS

[lochana-chathura]

• Also notice, variables that are listed already; pos, neg, and d, only the name is showing. Cannot expand those values and see what's inside.

Apparently, this is not specific to this scenario. Hence, extracted to a separate issue #42848