[LL] Set `isMetadataCompilation` correctly for metadata LL FIR sessions

- Some of the compiler functionality relies on the relatively new
  `isMetadataCompilation`, which indicates whether the compiler is
  performing metadata compilation. In the Analysis API, the property has
  a slightly different meaning: Instead of a sort of "global mode" of
  metadata compilation, it should determine whether the specific FIR
  session is a metadata session. When analyzing common modules, it then
  signals to the compiler that *this specific module* has to be analyzed
  as if we were performing metadata compilation.
- The commit fixes the LL FIR divergence in the `jvmRecordCommon`
  metadata diagnostic test. The fix in KT-85626 relies on
  `isMetadataCompilation` to determine `Vector`'s superclass.

^KT-82220

analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/sessions/factory/LLFirBuiltinsSessionFactory.kt

diff --git a/analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/sessions/factory/LLFirBuiltinsSessionFactory.kt b/analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/sessions/factory/LLFirBuiltinsSessionFactory.kt
index 77dc212..53651c4 100644
--- a/analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/sessions/factory/LLFirBuiltinsSessionFactory.kt
+++ b/analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/sessions/factory/LLFirBuiltinsSessionFactory.kt
@@ -98,7 +98,7 @@
             val languageVersionSettings = LanguageVersionSettingsImpl.DEFAULT
             registerIdeComponents(project, languageVersionSettings, builtinsModule.contentScope)
             register(FirLazyDeclarationResolver::class, FirDummyCompilerLazyDeclarationResolver)
-            registerCommonComponents(languageVersionSettings, isMetadataCompilation = false)
+            registerCommonComponents(languageVersionSettings, isMetadataCompilation = session.isMetadataSession)
             registerCommonComponentsAfterExtensionsAreConfigured()
             registerModuleData(moduleData)
 

analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/sessions/factory/LLFirSessionFactory.kt

diff --git a/analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/sessions/factory/LLFirSessionFactory.kt b/analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/sessions/factory/LLFirSessionFactory.kt
index d8a9b2b..9913f2e 100644
--- a/analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/sessions/factory/LLFirSessionFactory.kt
+++ b/analysis/low-level-api-fir/src/org/jetbrains/kotlin/analysis/low/level/api/fir/sessions/factory/LLFirSessionFactory.kt
@@ -303,7 +303,7 @@
             registerModuleData(moduleData)
             registerIdeComponents(project, languageVersionSettings, contentScope)
             register(FirLazyDeclarationResolver::class, FirDummyCompilerLazyDeclarationResolver)
-            registerCommonComponents(languageVersionSettings, isMetadataCompilation = false)
+            registerCommonComponents(languageVersionSettings, isMetadataCompilation = session.isMetadataSession)
             registerCommonComponentsAfterExtensionsAreConfigured()
             registerKdocDeserializer()
 
@@ -745,7 +745,7 @@
         annotationSearchScope: GlobalSearchScope,
     ) {
         registerIdeComponents(project, languageVersionSettings, annotationSearchScope)
-        registerCommonComponents(languageVersionSettings, isMetadataCompilation = false)
+        registerCommonComponents(languageVersionSettings, isMetadataCompilation = isMetadataSession)
         registerResolveComponents(KtRegisteredDiagnosticFactoriesStorage())
     }
 

compiler/fir/analysis-tests/testData/metadataDiagnostic/jvmRecordCommon.ll.kt

diff --git a/compiler/fir/analysis-tests/testData/metadataDiagnostic/jvmRecordCommon.ll.kt b/compiler/fir/analysis-tests/testData/metadataDiagnostic/jvmRecordCommon.ll.kt
deleted file mode 100644
index e38bf54..0000000
--- a/compiler/fir/analysis-tests/testData/metadataDiagnostic/jvmRecordCommon.ll.kt
+++ /dev/null
@@ -1,16 +0,0 @@
-// LL_FIR_DIVERGENCE
-// This test was recently introduced in the scope of KT-85626. Unfortunately, the fix doesn't work in the Analysis API out of the box
-// because it checks `isMetadataCompilation` for the session, which is only set in compiler mode.
-// LL_FIR_DIVERGENCE
-
-// METADATA_TARGET_PLATFORMS: JVM, JS
-// LANGUAGE: +MultiPlatformProjects
-// ISSUE: KT-85626
-// WITH_STDLIB
-// JVM_TARGET: 17
-
-@kotlin.jvm.JvmRecord
-data <!MISSING_DEPENDENCY_SUPERCLASS!>class Vector<!>(
-    <!MISSING_DEPENDENCY_SUPERCLASS!>val x: Float<!>,
-    <!MISSING_DEPENDENCY_SUPERCLASS!>val y: Float<!>,
-)

compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirLanguageSettingsComponent.kt

diff --git a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirLanguageSettingsComponent.kt b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirLanguageSettingsComponent.kt
index 8aef532..df704f8 100644
--- a/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirLanguageSettingsComponent.kt
+++ b/compiler/fir/tree/src/org/jetbrains/kotlin/fir/FirLanguageSettingsComponent.kt
@@ -18,5 +18,14 @@
 val FirSession.languageVersionSettings: LanguageVersionSettings
     get() = languageSettingsComponent.languageVersionSettings
 
+/**
+ * Whether the [FirSession] is used for metadata compilation, as opposed to compilation on a specific platform.
+ *
+ * In the compiler mode, the property is effectively global, since only one module is compiled at a time.
+ *
+ * In the Analysis API mode, [isMetadataCompilation] indicates whether the [FirSession] is a metadata session. Because the Analysis API can
+ * analyze multiple modules at the same time, the property does not determine any "global mode" of metadata compilation. Rather, it signals
+ * to the compiler that *this specific module* has to be analyzed as if we were performing metadata compilation.
+ */
 val FirSession.isMetadataCompilation: Boolean
     get() = languageSettingsComponent.isMetadataCompilation