Update Web3Core podspec to setup conditional building pipeline.

Author: yaroslavyaroslav

Sources/Core/Utility/BigUInt+Extension.swift

@@ -13,3 +13,16 @@ public extension BigUInt {
         self = value
     }
 }
+
+#if COCOAPODS
+extension BigUInt {
+    var isZero: Bool {
+        switch kind {
+        case .inline(0, 0): return true
+        case .array: return storage.isEmpty
+        default:
+            return false
+        }
+    }
+}
+#endif

Web3Core.podspec

@@ -1,4 +1,6 @@
 Pod::Spec.new do |spec|
+    spec.compiler_flags = '-DCOCOAPODS'
+
     spec.name         = 'Web3Core'
     spec.version      = '3.0.0'
     spec.module_name  = 'Core'
@@ -12,7 +14,7 @@ Pod::Spec.new do |spec|
     spec.swift_version = '5.5'
 
     spec.dependency 'secp256k1.c', '~> 0.1'
-    spec.dependency 'BigInt', '~> 5.2.0'
+    spec.dependency 'BigInt', '~> 5.2.0' # no newer version in pods.
     spec.dependency 'CryptoSwift', '~> 1.5.1'
     spec.source_files = "Sources/Core/**/*.swift"
 end