[FIR] Fix PACKAGE_CANNOT_BE_IMPORTED diagnostic

Don't report it when there is a function/property with the same name as
package

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsTestGenerated.java

@@ -11579,6 +11579,12 @@ public class FirOldFrontendDiagnosticsTestGenerated extends AbstractFirDiagnosti
                 runTest("compiler/testData/diagnostics/tests/imports/importFunctionWithAllUnderImportAfterNamedImport.kt");
             }
 
+            @Test
+            @TestMetadata("ImportFunctionWithPackageName.kt")
+            public void testImportFunctionWithPackageName() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/imports/ImportFunctionWithPackageName.kt");
+            }
+
             @Test
             @TestMetadata("ImportHidingDefinitionInTheSameFile.kt")
             public void testImportHidingDefinitionInTheSameFile() throws Exception {

compiler/fir/analysis-tests/tests-gen/org/jetbrains/kotlin/test/runners/FirOldFrontendDiagnosticsWithLightTreeTestGenerated.java

@@ -11579,6 +11579,12 @@ public class FirOldFrontendDiagnosticsWithLightTreeTestGenerated extends Abstrac
                 runTest("compiler/testData/diagnostics/tests/imports/importFunctionWithAllUnderImportAfterNamedImport.kt");
             }
 
+            @Test
+            @TestMetadata("ImportFunctionWithPackageName.kt")
+            public void testImportFunctionWithPackageName() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/imports/ImportFunctionWithPackageName.kt");
+            }
+
             @Test
             @TestMetadata("ImportHidingDefinitionInTheSameFile.kt")
             public void testImportHidingDefinitionInTheSameFile() throws Exception {

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirImportsChecker.kt

@@ -65,7 +65,9 @@ object FirImportsChecker : FirFileChecker() {
             }
         } else {
             val importedClassId = ClassId.topLevel(importedFqName)
-            if (importedClassId.resolveToClass(context) != null) {
+            if (importedClassId.resolveToClass(context) != null
+                || context.session.symbolProvider.getTopLevelCallableSymbols(importedFqName.parent(), importedName).isNotEmpty()
+            ) {
                 return
             }
             context.session.symbolProvider.getPackage(importedFqName)?.let {

compiler/testData/diagnostics/tests/imports/ImportFunctionWithPackageName.kt

@@ -0,0 +1,13 @@
+// FIR_IDENTICAL
+//FILE:a.kt
+package a.foo
+
+//FILE:b.kt
+package a
+
+fun foo() = 2
+
+//FILE:c.kt
+package c
+
+import a.foo

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/DiagnosticTestGenerated.java

@@ -11585,6 +11585,12 @@ public class DiagnosticTestGenerated extends AbstractDiagnosticTest {
                 runTest("compiler/testData/diagnostics/tests/imports/importFunctionWithAllUnderImportAfterNamedImport.kt");
             }
 
+            @Test
+            @TestMetadata("ImportFunctionWithPackageName.kt")
+            public void testImportFunctionWithPackageName() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/imports/ImportFunctionWithPackageName.kt");
+            }
+
             @Test
             @TestMetadata("ImportHidingDefinitionInTheSameFile.kt")
             public void testImportHidingDefinitionInTheSameFile() throws Exception {

idea/idea-frontend-fir/idea-fir-low-level-api/tests/org/jetbrains/kotlin/idea/fir/low/level/api/diagnostic/compiler/based/DiagnosisCompilerTestFE10TestdataTestGenerated.java

@@ -10097,6 +10097,11 @@ public class DiagnosisCompilerTestFE10TestdataTestGenerated extends AbstractDiag
                 runTest("compiler/testData/diagnostics/tests/imports/importFunctionWithAllUnderImportAfterNamedImport.kt");
             }
 
+            @TestMetadata("ImportFunctionWithPackageName.kt")
+            public void testImportFunctionWithPackageName() throws Exception {
+                runTest("compiler/testData/diagnostics/tests/imports/ImportFunctionWithPackageName.kt");
+            }
+
             @TestMetadata("ImportHidingDefinitionInTheSameFile.kt")
             public void testImportHidingDefinitionInTheSameFile() throws Exception {
                 runTest("compiler/testData/diagnostics/tests/imports/ImportHidingDefinitionInTheSameFile.kt");