FIR: support suspend functions #KT-24084 Fixed

compiler/fir/psi2fir/src/org/jetbrains/kotlin/fir/builder/RawFirBuilder.kt

@@ -548,6 +548,7 @@ class RawFirBuilder(val session: FirSession) {
                 function.hasModifier(KtTokens.INLINE_KEYWORD),
                 function.hasModifier(KtTokens.TAILREC_KEYWORD),
                 function.hasModifier(KtTokens.EXTERNAL_KEYWORD),
+                function.hasModifier(KtTokens.SUSPEND_KEYWORD),
                 function.receiverTypeReference.convertSafe(),
                 if (function.hasBlockBody()) {
                     typeReference.toFirOrUnitType()

compiler/fir/psi2fir/testData/rawBuilder/declarations/simpleFun.kt

@@ -1 +1,3 @@
-fun foo() {}
+fun foo() {}
+
+suspend fun bar() {}

compiler/fir/psi2fir/testData/rawBuilder/declarations/simpleFun.txt

@@ -1,3 +1,5 @@
 FILE: simpleFun.kt
     public? final? function foo(): kotlin.Unit {
     }
+    public? final? suspend function bar(): kotlin.Unit {
+    }