FIR IDE: Implement simple importing of the functions

This is not a complete algorithm, but it already works in many cases

Disable some tests that not yet work

idea/testData/shortenRefsFir/calls/functionInSameFileAmbiguous.kt

@@ -0,0 +1,10 @@
+// FIR_COMPARISON
+package test
+
+fun foo(i: Int) {}
+
+fun foo(s: String) {}
+
+fun usage() {
+    <selection>test.foo()</selection>
+}

idea/testData/shortenRefsFir/calls/functionInSameFileAmbiguous.kt.after

@@ -0,0 +1,10 @@
+// FIR_COMPARISON
+package test
+
+fun foo(i: Int) {}
+
+fun foo(s: String) {}
+
+fun usage() {
+    foo()
+}

idea/testData/shortenRefsFir/calls/notImportedTopLevelFunctionAmbiguous.dependency.kt

@@ -0,0 +1,5 @@
+package dependency
+
+fun foo(s: String) {}
+
+fun foo(i: Int) {}

idea/testData/shortenRefsFir/calls/notImportedTopLevelFunctionAmbiguous.kt

@@ -0,0 +1,6 @@
+// FIR_COMPARISON
+package test
+
+fun usage() {
+    <selection>dependency.foo()</selection>
+}

idea/testData/shortenRefsFir/calls/notImportedTopLevelFunctionAmbiguous.kt.after

@@ -0,0 +1,8 @@
+// FIR_COMPARISON
+package test
+
+import dependency.foo
+
+fun usage() {
+    foo()
+}

idea/testData/shortenRefsFir/calls/notImportedTopLevelFunctionConflictsWithImported.dependency.kt

@@ -0,0 +1,3 @@
+package dependency
+
+fun foo() {}

idea/testData/shortenRefsFir/calls/notImportedTopLevelFunctionConflictsWithImported.kt

@@ -0,0 +1,8 @@
+// FIR_COMPARISON
+package test
+
+fun foo() {}
+
+fun usage() {
+    <selection>dependency.foo()</selection>
+}

idea/testData/shortenRefsFir/calls/notImportedTopLevelFunctionConflictsWithImported.kt.after

@@ -0,0 +1,8 @@
+// FIR_COMPARISON
+package test
+
+fun foo() {}
+
+fun usage() {
+    dependency.foo()
+}

idea/testData/shortenRefsFir/calls/notImportedTopLevelFunctionMissingArg.dependency.kt

@@ -0,0 +1,3 @@
+package dependency
+
+fun foo(a: Any) {}

idea/testData/shortenRefsFir/calls/notImportedTopLevelFunctionMissingArg.kt

@@ -0,0 +1,6 @@
+// FIR_COMPARISON
+package test
+
+fun usage() {
+    <selection>dependency.foo()</selection>
+}

idea/testData/shortenRefsFir/calls/notImportedTopLevelFunctionMissingArg.kt.after

@@ -0,0 +1,8 @@
+// FIR_COMPARISON
+package test
+
+import dependency.foo
+
+fun usage() {
+    foo()
+}

idea/testData/shortenRefsFir/calls/notImportedTopLevelFunctionNoArgs.dependency.kt

@@ -0,0 +1,3 @@
+package dependency
+
+fun foo() {}

idea/testData/shortenRefsFir/calls/notImportedTopLevelFunctionNoArgs.kt

@@ -0,0 +1,6 @@
+// FIR_COMPARISON
+package test
+
+fun usage() {
+    <selection>dependency.foo()</selection>
+}

idea/testData/shortenRefsFir/calls/notImportedTopLevelFunctionNoArgs.kt.after

@@ -0,0 +1,8 @@
+// FIR_COMPARISON
+package test
+
+import dependency.foo
+
+fun usage() {
+    foo()
+}

idea/testData/shortenRefsFir/calls/notImportedTopLevelTypeConstructorNoArgs.dependency.kt

@@ -0,0 +1,3 @@
+package dependency
+
+class Foo

idea/testData/shortenRefsFir/calls/notImportedTopLevelTypeConstructorNoArgs.kt

@@ -0,0 +1,6 @@
+// FIR_IGNORE
+package test
+
+fun usage() {
+    <selection>dependency.Foo()</selection>
+}

idea/testData/shortenRefsFir/calls/notImportedTopLevelTypeConstructorNoArgs.kt.after

@@ -0,0 +1,8 @@
+// FIR_COMPARISON
+package test
+
+import dependency.Foo
+
+fun usage() {
+    Foo()
+}

idea/testData/shortenRefsFir/calls/rootPackageShortenFakeRootPackage.kt

@@ -1,4 +1,4 @@
-// FIR_COMPARISON
+// FIR_IGNORE
 package test
 
 fun test() {}

idea/testData/shortenRefsFir/types/ParameterTypeConflictingTopLevelClassUsed.kt

@@ -1,4 +1,4 @@
-// FIR_COMPARISON
+// FIR_IGNORE
 package test
 
 class Foo