improvement: Update mtags to 1.4.0 and backport remaining changes

presentation-compiler/src/main/dotty/tools/pc/printer/ShortenedTypePrinter.scala

@@ -3,6 +3,7 @@ package dotty.tools.pc.printer
 import scala.collection.mutable
 import scala.meta.internal.jdk.CollectionConverters.*
 import scala.meta.internal.metals.ReportContext
+import scala.meta.internal.mtags.KeywordWrapper
 import scala.meta.pc.SymbolDocumentation
 import scala.meta.pc.SymbolSearch
 
@@ -64,6 +65,11 @@ class ShortenedTypePrinter(
 
   private val foundRenames = collection.mutable.LinkedHashMap.empty[Symbol, String]
 
+  override def nameString(name: Name): String =
+    val nameStr = super.nameString(name)
+    if (nameStr.nonEmpty) KeywordWrapper.Scala3Keywords.backtickWrap(nameStr)
+    else nameStr
+
   def getUsedRenames: Map[Symbol, String] =
     foundRenames.toMap.filter { case (k, v) => k.showName != v }
 

presentation-compiler/test/dotty/tools/pc/tests/completion/CompletionKeywordSuite.scala

@@ -433,6 +433,7 @@ class CompletionKeywordSuite extends BaseCompletionSuite:
          |given
          |extension
          |type
+         |opaque type
          |class
          |enum
          |case class

presentation-compiler/test/dotty/tools/pc/tests/completion/CompletionSuite.scala

@@ -1136,7 +1136,7 @@ class CompletionSuite extends BaseCompletionSuite:
           |  scala@@
           |}
           |""".stripMargin,
-      """|scala <root>
+      """|scala `<root>`
          |""".stripMargin
     )
 
@@ -1726,8 +1726,8 @@ class CompletionSuite extends BaseCompletionSuite:
     check(
       """|import @@
          |""".stripMargin,
-      """|java <root>
-         |javax <root>
+      """|java `<root>`
+         |javax `<root>`
          |""".stripMargin,
       filter = _.startsWith("java")
     )
@@ -1745,8 +1745,8 @@ class CompletionSuite extends BaseCompletionSuite:
     check(
       """|export @@
          |""".stripMargin,
-      """|java <root>
-         |javax <root>
+      """|java `<root>`
+         |javax `<root>`
          |""".stripMargin,
       filter = _.startsWith("java")
     )

presentation-compiler/test/dotty/tools/pc/tests/edit/InsertInferredTypeSuite.scala

@@ -597,6 +597,78 @@ class InsertInferredTypeSuite extends BaseCodeActionSuite:
          |""".stripMargin
     )
 
+  @Test def `backticks-4` =
+  checkEdit(
+    """|case class `Foo-Foo`(i: Int)
+       |object O{
+       |  val <<foo>> = `Foo-Foo`(1)
+       |}""".stripMargin,
+    """|case class `Foo-Foo`(i: Int)
+       |object O{
+       |  val foo: `Foo-Foo` = `Foo-Foo`(1)
+       |}
+       |""".stripMargin
+  )
+
+
+  @Test def `backticks-5` =
+    checkEdit(
+      """|object A{
+         |  case class `Foo-Foo`(i: Int)
+         |}
+         |object O{
+         |  val <<foo>> = A.`Foo-Foo`(1)
+         |}""".stripMargin,
+      """|import A.`Foo-Foo`
+         |object A{
+         |  case class `Foo-Foo`(i: Int)
+         |}
+         |object O{
+         |  val foo: `Foo-Foo` = A.`Foo-Foo`(1)
+         |}
+         |""".stripMargin
+    )
+
+
+  @Test def `backticks-6` =
+    checkEdit(
+      """|object A{
+         |  case class `Foo-Foo`[A](i: A)
+         |}
+         |object O{
+         |  val <<foo>> = A.`Foo-Foo`(1)
+         |}""".stripMargin,
+      """|import A.`Foo-Foo`
+         |object A{
+         |  case class `Foo-Foo`[A](i: A)
+         |}
+         |object O{
+         |  val foo: `Foo-Foo`[Int] = A.`Foo-Foo`(1)
+         |}
+         |""".stripMargin
+    )
+
+  @Test def `backticks-7` =
+    checkEdit(
+      """|object A{
+         |  class `x-x`
+         |  case class Foo[A](i: A)
+         |}
+         |object O{
+         |  val <<foo>> = A.Foo(new A.`x-x`)
+         |}""".stripMargin,
+      """|import A.Foo
+         |import A.`x-x`
+         |object A{
+         |  class `x-x`
+         |  case class Foo[A](i: A)
+         |}
+         |object O{
+         |  val foo: Foo[`x-x`] = A.Foo(new A.`x-x`)
+         |}
+         |""".stripMargin
+    )
+
   @Test def `literal-types1` =
     checkEdit(
       """|object O {

project/Build.scala

@@ -1434,7 +1434,7 @@ object Build {
       BuildInfoPlugin.buildInfoDefaultSettings
 
   lazy val presentationCompilerSettings = {
-    val mtagsVersion = "1.3.5"
+    val mtagsVersion = "1.4.0+13-e3812b3f-SNAPSHOT"
     Seq(
       libraryDependencies ++= Seq(
         "org.lz4" % "lz4-java" % "1.8.0",