Fix #133: Highlight inline as a soft keyword

If it is part of an inline `if` or `match` it is highlighted as a control flow keyword.
If it is part of a `def` or `val` definition it is highlighted as a declaration keyword.
Otherwise, it is not highlighted.

Author: nicolasstucki

src/typescript/Scala.tmLanguage.ts

@@ -263,6 +263,9 @@ export const scalaTmLanguage: TmLanguage = {
         {
           include: '#singleton-type'
         },
+        {
+          include: '#inline'
+        },
         {
           include: '#scala-quoted'
         },
@@ -571,6 +574,26 @@ export const scalaTmLanguage: TmLanguage = {
         }
       }
     },
+    inline: {
+      patterns: [
+        {
+          match: `\\b(inline)\\b(?=(\\s+(?:${plainid}|${backQuotedId})\\s*:)|(.*(val|def)))`,
+          captures: {
+            '1': {
+              name: 'storage.modifier.other'
+            }
+          }
+        },
+        {
+          match: `\\b(inline)\\b(?=.*(if|match))`,
+          captures: {
+            '1': {
+              name: 'keyword.control.flow.scala'
+            }
+          }
+        }
+      ]
+    },
     'scala-quoted': {
       match: "('\\{|'\\[)(?!')",
       name: 'constant.other.quoted.scala'
@@ -822,7 +845,7 @@ export const scalaTmLanguage: TmLanguage = {
           name: 'storage.modifier.access'
         },
         {
-          match: '\\b(synchronized|@volatile|abstract|final|lazy|sealed|implicit|inline |opaque |override|@transient|@native)\\b',
+          match: '\\b(synchronized|@volatile|abstract|final|lazy|sealed|implicit|opaque |override|@transient|@native)\\b',
           name: 'storage.modifier.other'
         }
       ]

tests/unit/#133.test.scala

@@ -0,0 +1,41 @@
+// SYNTAX TEST "source.scala"
+
+
+    inline val c = 0
+//  ^^^^^^ storage.modifier.other
+
+    inline def power(x: Double, inline n: Int): Double =
+//  ^^^^^^ storage.modifier.other
+//                              ^^^^^^ storage.modifier.other
+      inline if (n == 0) 1.0
+//    ^^^^^^ keyword.control.flow.scala
+      else inline if (n % 2 == 1) x * power(x, n - 1)
+//         ^^^^^^ keyword.control.flow.scala
+      else power(x * x, n / 2)
+ 
+
+    inline x match {
+//  ^^^^^^ keyword.control.flow.scala
+//           ^^^^^ keyword.control.flow.scala
+
+
+    inline def power(x: Double, inline N: Int): Double =
+//  ^^^^^^ storage.modifier.other
+//                              ^^^^^^ storage.modifier.other
+
+    inline def power(x: Double, inline `n`: Int): Double =
+//  ^^^^^^ storage.modifier.other
+//                              ^^^^^^ storage.modifier.other
+
+val x = inline + 2
+//      ^^^^^^ - storage.modifier.other keyword.control.flow.scala
+val x = inline(x)
+//      ^^^^^^ - storage.modifier.other keyword.control.flow.scala
+val x = inline[T]
+//      ^^^^^^ - storage.modifier.other keyword.control.flow.scala
+
+    inline def inline(inline inline: Int): Double =
+//  ^^^^^^ storage.modifier.other
+//             ^^^^^^ entity.name.function.declaration
+//                    ^^^^^^ storage.modifier.other
+//                           ^^^^^^ variable.parameter.scala