Allow -Infinity as an enum property name

Author: fabiancook

src/compiler/checker.ts

@@ -10034,7 +10034,7 @@ namespace ts {
         }
 
         function isInfinityOrNaNString(name: string) : boolean {
-            return name === 'Infinity' || name === 'NaN';
+            return name === 'Infinity' || name === '-Infinity' || name === 'NaN';
         }
 
         function isNumericLiteralName(name: string) {

tests/baselines/reference/enumWithNegativeInfinityProperty.js

@@ -0,0 +1,11 @@
+//// [enumWithNegativeInfinityProperty.ts]
+enum A {
+    "-Infinity" = 1
+}
+
+
+//// [enumWithNegativeInfinityProperty.js]
+var A;
+(function (A) {
+    A[A["-Infinity"] = 1] = "-Infinity";
+})(A || (A = {}));

tests/baselines/reference/enumWithNegativeInfinityProperty.symbols

@@ -0,0 +1,7 @@
+=== tests/cases/compiler/enumWithNegativeInfinityProperty.ts ===
+enum A {
+>A : Symbol(A, Decl(enumWithNegativeInfinityProperty.ts, 0, 0))
+
+    "-Infinity" = 1
+}
+

tests/baselines/reference/enumWithNegativeInfinityProperty.types

@@ -0,0 +1,8 @@
+=== tests/cases/compiler/enumWithNegativeInfinityProperty.ts ===
+enum A {
+>A : A
+
+    "-Infinity" = 1
+>1 : number
+}
+

tests/cases/compiler/enumWithNegativeInfinityProperty.ts

@@ -0,0 +1,3 @@
+enum A {
+    "-Infinity" = 1
+}