[FIR] Fix isMyTypeVariable in ConeInferenceContext

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/ConeInferenceContext.kt

@@ -241,7 +241,7 @@ interface ConeInferenceContext : TypeSystemInferenceExtensionContext,
 
     override fun KotlinTypeMarker.mayBeTypeVariable(): Boolean {
         require(this is ConeKotlinType)
-        return this is ConeTypeVariableType
+        return this.typeConstructor() is ConeTypeVariableTypeConstructor
     }
 
     override fun CapturedTypeMarker.typeConstructorProjection(): TypeArgumentMarker {

compiler/fir/resolve/testData/resolve/stdlib/j+k/typeParameterUse.kt

@@ -0,0 +1,19 @@
+// FULL_JDK
+// FILE: U.java
+import org.jetbrains.annotations.NotNull;
+public class U {
+
+    @NotNull
+    public <T> T getValue(Box<@NotNull T> box) {}
+}
+
+// FILE: Box.java
+
+public class Box<T> {}
+
+
+// FILE: useSite.kt
+fun foo(holder: U, box: Box<Int>): Int {
+
+    return holder.getValue(box)
+}

compiler/fir/resolve/testData/resolve/stdlib/j+k/typeParameterUse.txt

@@ -0,0 +1,4 @@
+FILE: useSite.kt
+    public final fun foo(holder: R|U|, box: R|Box<kotlin/Int>|): R|kotlin/Int| {
+        ^foo R|<local>/holder|.R|/U.getValue|<R|kotlin/Int|>(R|<local>/box|)
+    }

compiler/fir/resolve/tests/org/jetbrains/kotlin/fir/FirDiagnosticsWithStdlibTestGenerated.java

@@ -513,6 +513,11 @@ public class FirDiagnosticsWithStdlibTestGenerated extends AbstractFirDiagnostic
         public void testStaticGenericMethod() throws Exception {
             runTest("compiler/fir/resolve/testData/resolve/stdlib/j+k/StaticGenericMethod.kt");
         }
+
+        @TestMetadata("typeParameterUse.kt")
+        public void testTypeParameterUse() throws Exception {
+            runTest("compiler/fir/resolve/testData/resolve/stdlib/j+k/typeParameterUse.kt");
+        }
     }
 
     @TestMetadata("compiler/fir/resolve/testData/resolve/stdlib/problems")