Fixed Literal value in signature (dotnet#7901)

* Fixed literal sig from breaking subsequent sigs

* Added tests for literal sig

* Fixed test

* Fixed test name

src/fsharp/pars.fsy

@@ -788,7 +788,7 @@ optLiteralValueSpfn:
   | EQUALS declExpr 
       { Some($2) }
 
-  | EQUALS OBLOCKBEGIN declExpr oblockend 
+  | EQUALS OBLOCKBEGIN declExpr oblockend opt_ODECLEND
       { Some($3) }
 
 

tests/fsharp/tests.fs

@@ -2155,6 +2155,12 @@ module TypecheckTests =
         fsc cfg "%s --target:library -o:pos32.dll --warnaserror" cfg.fsc_flags ["pos32.fs"]
         peverify cfg "pos32.dll"
 
+    [<Test>]
+    let ``sigs pos33`` () = 
+        let cfg = testConfig "typecheck/sigs"
+        fsc cfg "%s --target:library -o:pos33.dll --warnaserror" cfg.fsc_flags ["pos33.fsi"; "pos33.fs"]
+        peverify cfg "pos33.dll"
+
     [<Test>]
     let ``sigs pos23`` () = 
         let cfg = testConfig "typecheck/sigs"

tests/fsharp/typecheck/sigs/pos33.fs

@@ -0,0 +1,11 @@
+module Pos33
+
+let x = 1
+[<Literal>]
+let y = 1
+let z = 1
+[<Literal>]
+let w = "w"
+let q = "q"
+[<Literal>]
+let u = "u"

tests/fsharp/typecheck/sigs/pos33.fsi

@@ -0,0 +1,12 @@
+module Pos33
+
+val x : int
+[<Literal>]
+val y : int = 1
+val z : int
+[<Literal>]
+val w : string = "w"
+val q : string
+[<Literal>]
+val u : string = 
+ "u"