Don't show hint for parameter with explicitly specified type

idea/src/org/jetbrains/kotlin/idea/parameterInfo/KotlinInlayParameterHintsProvider.kt

@@ -55,7 +55,7 @@ enum class HintType(desc: String, enabled: Boolean) {
         }
 
         override fun isApplicable(elem: PsiElement): Boolean = (elem is KtProperty && elem.getReturnTypeReference() == null && elem.isLocal) ||
-                                                               (elem is KtParameter && elem.isLoopParameter)
+                                                               (elem is KtParameter && elem.isLoopParameter && elem.typeReference == null)
     },
 
     FUNCTION_HINT("Show function return type hints", false) {

idea/tests/org/jetbrains/kotlin/idea/parameterInfo/InlayTypeHintsTest.kt

@@ -46,4 +46,14 @@ class InlayTypeHintsTest : KotlinLightCodeInsightFixtureTestCase() {
         HintType.PROPERTY_HINT.option.set(true)
         check("""val a = Any()""")
     }
+
+    fun testLoopParameter() {
+        HintType.LOCAL_VARIABLE_HINT.option.set(true)
+        check("""fun foo() { for (x<hint text=": String" /> in listOf("a")) { } }""")
+    }
+
+    fun testLoopParameterWithExplicitType() {
+        HintType.LOCAL_VARIABLE_HINT.option.set(true)
+        check("""fun foo() { for (x: String in listOf("a")) { } }""")
+    }
 }