gopls/internal/test/marker: re-enable some tests

Re-enable (with adjustment) some tests that were disabled while staging
standard library changes to parsing and printing.

Fixes golang/go#54822

Change-Id: I7d54ce96b10f294dae257e8403983b25541a158f
Reviewed-on: https://go-review.googlesource.com/c/tools/+/557397
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Alan Donovan <adonovan@google.com>

gopls/internal/test/marker/testdata/completion/nested_complit.txt

@@ -1,9 +1,11 @@
 This test checks completion of nested composite literals;
 
-TODO(rfindley): investigate an un-skip the disabled test below.
+Parser recovery changed in Go 1.20, so this test requires at least that
+version for consistency.
 
 -- flags --
 -ignore_extra_diags
+-min_go=go1.20
 
 -- nested_complit.go --
 package nested_complit
@@ -15,9 +17,10 @@ type ncBar struct { //@item(structNCBar, "ncBar", "struct{...}", "struct")
 }
 
 func _() {
-	[]ncFoo{} //@item(litNCFoo, "[]ncFoo{}", "", "var")
+	_ = []ncFoo{} //@item(litNCFoo, "[]ncFoo{}", "", "var")
+	_ = make([]ncFoo, 0) //@item(makeNCFoo, "make([]ncFoo, 0)", "", "func")
+
 	_ := ncBar{
-		// disabled - see issue #54822
-		baz: [] // complete(" //", structNCFoo, structNCBar)
+		baz: [] //@complete(" //", litNCFoo, makeNCFoo, structNCBar, structNCFoo)
 	}
 }

gopls/internal/test/marker/testdata/hover/generics.txt

@@ -1,9 +1,10 @@
 This file contains tests for hovering over generic Go code.
 
-Requires go1.19+ for the new go/doc/comment package.
+Requires go1.20+ for the new go/doc/comment package, and a change in Go 1.20
+that affected the formatting of constraint interfaces.
 
 -- flags --
--min_go=go1.19
+-min_go=go1.20
 
 -- go.mod --
 // A go.mod is require for correct pkgsite links.
@@ -25,10 +26,8 @@ type Value[T any] struct { //@hover("T", "T", ValueT)
 	Q   int //@hover("Q", "Q", ValueQ)
 }
 
-// disabled - see issue #54822
-func F[P interface{ ~int | string }]() { // hover("P","P",Ptparam)
-	// disabled - see issue #54822
-	var _ P // hover("P","P",Pvar)
+func F[P interface{ ~int | string }]() { //@hover("P", "P", Ptparam)
+	var _ P //@hover("P","P",Pvar)
 }
 
 -- inferred.go --
@@ -76,3 +75,11 @@ field Q int
 ```go
 type parameter T any
 ```
+-- @Ptparam --
+```go
+type parameter P interface{~int | string}
+```
+-- @Pvar --
+```go
+type parameter P interface{~int | string}
+```