[Analysis API] Test 'IGNORE_SELF' mode in context collector tests

Parent declarations of the file copy are typically unresolved in the
'IGNORE_SELF' mode, as the declaration designation contains declarations
from the original file.

analysis/low-level-api-fir/testData/contextCollector/smartCasts/plainCheck.copy.txt

@@ -0,0 +1,40 @@
+Tower Data Context:
+    Element 0
+        Scope: FirDefaultStarImportingScope
+    Element 1
+        Scope: FirExplicitStarImportingScope
+    Element 2
+        Scope: FirDefaultSimpleImportingScope
+    Element 3
+        Scope: FirDefaultSimpleImportingScope
+    Element 4
+        Scope: FirPackageMemberScope
+    Element 5
+        Scope: FirExplicitSimpleImportingScope
+    Element 6
+        Scope: FirLocalScope
+            Properties:
+                FirValueParameterSymbol another: R|Foo|
+                FirValueParameterSymbol obj: R|kotlin/Any|
+    Element 7
+        Scope: FirLocalScope
+    Element 8
+        Scope: FirLocalScope
+Smart Casts:
+    FirValueParameterSymbol obj: R|kotlin/Any|
+    Types:
+        Foo
+        kotlin.Any
+
+FILE: [ResolvedTo(IMPORTS)] plainCheck.kt
+    public final? [ResolvedTo(RAW_FIR)] interface Foo : R|kotlin/Any| {
+    }
+    public final [ResolvedTo(BODY_RESOLVE)] fun test([ResolvedTo(BODY_RESOLVE)] obj: R|kotlin/Any|, [ResolvedTo(BODY_RESOLVE)] another: R|Foo|): R|kotlin/Unit| {
+        when () {
+            (R|<local>/obj| is R|Foo|) ->  {
+                R|/consume|(R|<local>/another|)
+            }
+        }
+
+    }
+    public? final? [ResolvedTo(RAW_FIR)] fun consume([ResolvedTo(RAW_FIR)] obj: Foo): R|kotlin/Unit| { LAZY_BLOCK }