Fix CI: replace LINQ extension test case with instance method; format IlxGen.fs

- Replace List<int>.First() (LINQ extension, fails on net472) with
  List<int>.Contains(1) (instance method, works on all TFMs)
- Run fantomas on IlxGen.fs

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: T-Gro

src/Compiler/CodeGen/IlxGen.fs

@@ -8676,11 +8676,7 @@ and GenBindingAfterDebugPoint cenv cgbuf eenv bind isStateVar startMarkOpt =
         CommitStartScope cgbuf startMarkOpt
 
     // The initialization code for static 'let' and 'do' bindings gets compiled into the initialization .cctor for the whole file
-    | _ when
-        vspec.IsClassConstructor
-        && isNil vspec.DeclaringEntity.Typars
-        && not isStateVar
-        ->
+    | _ when vspec.IsClassConstructor && isNil vspec.DeclaringEntity.Typars && not isStateVar ->
         let tps, _, _, _, cctorBody, _ =
             IteratedAdjustLambdaToMatchValReprInfo g cenv.amap vspec.ValReprInfo.Value rhsExpr
 

tests/FSharp.Compiler.ComponentTests/Language/Nullness/NullableReferenceTypesTests.fs

@@ -2384,8 +2384,8 @@ let main _ = 0
              2, 28, 29, "Trim", "x", "string | null")>]
 [<InlineData("module MyLib\nlet f (x: string | null) = x.Split(',')",
              2, 28, 29, "Split", "x", "string | null")>]
-[<InlineData("module MyLib\nopen System.Linq\nlet f (xs: System.Collections.Generic.List<int> | null) = xs.First()",
-             3, 59, 61, "First", "xs", "int seq | null")>]
+[<InlineData("module MyLib\nlet f (xs: System.Collections.Generic.List<int> | null) = xs.Contains(1)",
+             2, 59, 61, "Contains", "xs", "System.Collections.Generic.List<int> | null")>]
 [<InlineData("module MyLib\nlet f (xs: System.Collections.Generic.IEnumerable<int> | null) = xs.GetEnumerator()",
              2, 66, 68, "GetEnumerator", "xs", "System.Collections.Generic.IEnumerable<int> | null")>]
 [<InlineData("module MyLib\nopen System.Text\nlet f (sb: StringBuilder | null) = sb.Length <- 0",