Add /** */ to cpp/language-configurations.json (microsoft#211202)

This fixes the issue at microsoft/vscode-cpptools#12249 .

This was removed in microsoft@98fa77a .

Then PR microsoft#160357 added /* */ autoClosingPair.

Author: sean-mcmanus

extensions/cpp/language-configuration.json

@@ -14,7 +14,8 @@
 		{ "open": "(", "close": ")" },
 		{ "open": "'", "close": "'", "notIn": ["string", "comment"] },
 		{ "open": "\"", "close": "\"", "notIn": ["string"] },
-		{ "open": "/*", "close": "*/", "notIn": ["string", "comment"] }
+		{ "open": "/*", "close": "*/", "notIn": ["string", "comment"] },
+		{ "open": "/**", "close": " */", "notIn": ["string"] }
 	],
 	"surroundingPairs": [
 		["{", "}"],