[gf] Remove C4018 warnings from GfNumericCast

boolean types are considered (unsigned) integral types.
Using boolean types with GfNumericCast would implicitly cast to a signed
integer in GfIntegerCompareLess, causing Windows to issue C4018 warnings
boolean types are now explicitly handled in GfNumericCast

Author: nvidia-jomiller

pxr/base/gf/numericCast.h

@@ -86,9 +86,27 @@ GfNumericCast(From from, GfNumericCastFailureType *failType = nullptr)
         };
     };
 
+    // bool -> int
+    if constexpr (std::is_same_v<From, bool> && std::is_integral_v<To>) {
+        // No need to range check bool to int
+        return from ? static_cast<To>(1) : static_cast<To>(0);
+    }
+    // int -> bool
+    else if constexpr (std::is_integral_v<From> && std::is_same_v<To, bool>) {
+        // Range check int to bool
+        if (GfIntegerCompareLess(from, 0)) {
+            setFail(GfNumericCastNegOverflow);
+            return {};
+        }
+        if (GfIntegerCompareLess(1, from)) {
+            setFail(GfNumericCastPosOverflow);
+            return {};
+        }
+        return from != 0;
+    }
     // int -> int.
-    if constexpr (std::is_integral_v<From> &&
-                  std::is_integral_v<To>) {
+    else if constexpr (std::is_integral_v<From> &&
+                       std::is_integral_v<To>) {
         // Range check integer to integer.
         if (GfIntegerCompareLess(from, ToLimits::min())) {
             setFail(GfNumericCastNegOverflow);