FIx tests after renaming platform to header.

idea/idea-completion/testData/keywords/InModifierListInsideClass.kt

@@ -3,5 +3,5 @@ open class Foo {
     p<caret> val foo = 1
 }
 
-// EXIST: private, public, protected, platform
+// EXIST: private, public, protected
 // NOTHING_ELSE

idea/idea-completion/testData/keywords/PrefixMatcher.kt

@@ -5,5 +5,4 @@ p<caret>
 // EXIST:  package
 // EXIST:  private
 // EXIST:  public
-// EXIST:  header
 // NOTHING_ELSE

idea/tests/org/jetbrains/kotlin/asJava/KtFileLightClassTest.kt

@@ -63,7 +63,7 @@ class KtFileLightClassTest : KotlinLightCodeInsightFixtureTestCase() {
     }
 
     fun testNoFacadeForHeaderClass() {
-        val file = myFixture.configureByText("foo.kt", "platform fun foo(): Int") as KtFile
+        val file = myFixture.configureByText("foo.kt", "header fun foo(): Int") as KtFile
         assertEquals(0, file.classes.size)
         val facadeFiles = LightClassGenerationSupport.getInstance(project).findFilesForFacade(FqName("foo.FooKt"), GlobalSearchScope.allScope(project))
         assertEquals(0, facadeFiles.size)

idea/tests/org/jetbrains/kotlin/asJava/LightClassFromTextTest.kt

@@ -97,7 +97,7 @@ class LightClassFromTextTest : KotlinLightCodeInsightFixtureTestCase() {
     }
 
     fun testHeaderDeclarations() {
-        val contextFile = myFixture.configureByText("Header.kt", "platform class Foo\n\nplatform fun foo()\n") as KtFile
+        val contextFile = myFixture.configureByText("Header.kt", "header class Foo\n\nheader fun foo()\n") as KtFile
         val headerClass = contextFile.declarations.single { it is KtClassOrObject }
         assertEquals(0, headerClass.toLightElements().size)
         val headerFunction = contextFile.declarations.single { it is KtNamedFunction }