fix: improve EJSON generation for previously skipped edge cases

These cases were explicitly disabled in the BSON corpus test runner
but are now supported.

Author: mbroadst

Diff for: lib/double.js

@@ -1,4 +1,5 @@
 'use strict';
+
 /**
  * A class representation of the BSON Double type.
  */
@@ -41,16 +42,22 @@ class Double {
     if (options && (options.legacy || (options.relaxed && isFinite(this.value)))) {
       return this.value;
     }
-    return { $numberDouble: this.value.toString() };
+
+    if (Object.is(Math.sign(this.value), -0)) {
+      return { $numberDouble: `-${this.value.toFixed(1)}` };
+    }
+
+    return {
+      $numberDouble: Number.isInteger(this.value) ? this.value.toFixed(1) : this.value.toString()
+    };
   }
 
   /**
    * @ignore
    */
   static fromExtendedJSON(doc, options) {
-    return options && options.relaxed
-      ? parseFloat(doc.$numberDouble)
-      : new Double(parseFloat(doc.$numberDouble));
+    const doubleValue = parseFloat(doc.$numberDouble);
+    return options && options.relaxed ? doubleValue : new Double(doubleValue);
   }
 }