hermes | sandbox | Explicitly use the unsigned int32 for SandboxValue…

…Kind to prevent sign bit to be used for the pointer mask.

Summary:
By default this will change the sign bit on the integer and we'll get a warning about overflow.
Explicitly qualify the values as unsigned to prevent that from happening.

Reviewed By: neildhar

Differential Revision: D54602929

fbshipit-source-id: 6e806dbb04403ce2c4346a179ce17062cfa0aae5

API/hermes_sandbox/HermesSandboxRuntime.cpp

@@ -109,18 +109,18 @@ struct SandboxPropNameIDListPtrOrError {
 };
 
 /// Always set the top bit for pointers so they can be easily checked.
-#define SANDBOX_POINTER_MASK (1 << 31)
+#define SANDBOX_POINTER_MASK (1u << 31)
 
-enum SandboxValueKind {
+enum SandboxValueKind : uint32_t {
   SandboxValueKindUndefined = 0,
   SandboxValueKindNull = 1,
   SandboxValueKindBoolean = 2,
   SandboxValueKindError = 3,
   SandboxValueKindNumber = 4,
-  SandboxValueKindSymbol = 5 | SANDBOX_POINTER_MASK,
-  SandboxValueKindBigInt = 6 | SANDBOX_POINTER_MASK,
-  SandboxValueKindString = 7 | SANDBOX_POINTER_MASK,
-  SandboxValueKindObject = 9 | SANDBOX_POINTER_MASK,
+  SandboxValueKindSymbol = 5u | SANDBOX_POINTER_MASK,
+  SandboxValueKindBigInt = 6u | SANDBOX_POINTER_MASK,
+  SandboxValueKindString = 7u | SANDBOX_POINTER_MASK,
+  SandboxValueKindObject = 9u | SANDBOX_POINTER_MASK,
 };
 
 struct SandboxValue {