Fixes JSDoc @type function with variable args is interpreted incorrectly (#44864)

* Fixes #44386

* Add test

* Move test from fourslash to conformance

Author: jeanp413

src/compiler/checker.ts

@@ -12290,7 +12290,7 @@ namespace ts {
 
                     // Record a new minimum argument count if this is not an optional parameter
                     const isOptionalParameter = isOptionalJSDocPropertyLikeTag(param) ||
-                        param.initializer || param.questionToken || param.dotDotDotToken ||
+                        param.initializer || param.questionToken || isRestParameter(param) ||
                         iife && parameters.length > iife.arguments.length && !type ||
                         isJSDocOptionalParameter(param);
                     if (!isOptionalParameter) {

tests/baselines/reference/jsdocVariadicType.symbols

@@ -0,0 +1,14 @@
+=== tests/cases/conformance/jsdoc/a.js ===
+/**
+ * @type {function(boolean, string, ...*):void}
+ */
+const foo = function (a, b, ...r) { };
+>foo : Symbol(foo, Decl(a.js, 3, 5))
+>a : Symbol(a, Decl(a.js, 3, 22))
+>b : Symbol(b, Decl(a.js, 3, 24))
+>r : Symbol(r, Decl(a.js, 3, 27))
+
+=== tests/cases/conformance/jsdoc/b.ts ===
+foo(false, '');
+>foo : Symbol(foo, Decl(a.js, 3, 5))
+

tests/baselines/reference/jsdocVariadicType.types

@@ -0,0 +1,18 @@
+=== tests/cases/conformance/jsdoc/a.js ===
+/**
+ * @type {function(boolean, string, ...*):void}
+ */
+const foo = function (a, b, ...r) { };
+>foo : (arg0: boolean, arg1: string, ...arg2: any[]) => void
+>function (a, b, ...r) { } : (a: boolean, b: string, ...r: any[]) => void
+>a : boolean
+>b : string
+>r : any[]
+
+=== tests/cases/conformance/jsdoc/b.ts ===
+foo(false, '');
+>foo(false, '') : void
+>foo : (arg0: boolean, arg1: string, ...arg2: any[]) => void
+>false : false
+>'' : ""
+

tests/cases/conformance/jsdoc/jsdocVariadicType.ts

@@ -0,0 +1,12 @@
+// @allowJS: true
+// @checkJs: true
+// @noEmit: true
+
+// @filename: a.js
+/**
+ * @type {function(boolean, string, ...*):void}
+ */
+const foo = function (a, b, ...r) { };
+
+// @filename: b.ts
+foo(false, '');