[ios] expose explict module for c & cpp

- standard user can import spine-c based api without c warning
- dedicated user can import cpp interface with explict import and enabling cpp interp
- objective-c user can not import cpp using objective-c++ without issue

Author: pbk20191

Package.swift

@@ -41,17 +41,8 @@ let package = Package(
             name: "SpineC",
             path: "spine-ios/Sources/SpineC",
             sources: [
-                "spine-c/src/extensions.cpp",
-                "spine-c/src/generated",
-                "spine-cpp/src/spine"
-            ],
-            publicHeadersPath: "spine-c/include",
-            cxxSettings: [
-                .headerSearchPath("spine-c/include"),
-                .headerSearchPath("spine-c/src"),
-                .headerSearchPath("spine-c/src/generated"),
-                .headerSearchPath("spine-cpp/include"),
-                .headerSearchPath("spine-cpp/src"),
+                "src",
+                "spine"
             ],
             linkerSettings: [
                 .linkedLibrary("c++")

spine-c/include/module.modulemap

@@ -1,4 +1,13 @@
 module SpineC {
-    header "spine-c.h"
-    export *
-}
+    use c
+    export c
+    explicit module cpp {
+        umbrella header "spine/spine.h"
+        requires cplusplus11
+        export *
+    }
+    explicit module c {
+        header "spine-c.h"
+        export *
+    }
+}

spine-ios/Sources/SpineC/include/module.modulemap

@@ -0,0 +1 @@
+../../../../spine-c/include/module.modulemap

spine-ios/Sources/SpineC/include/spine

@@ -0,0 +1 @@
+../../../../spine-cpp/include/spine

spine-ios/Sources/SpineC/include/spine-c.h

@@ -0,0 +1 @@
+../../../../spine-c/include/spine-c.h

spine-ios/Sources/SpineC/spine

@@ -0,0 +1 @@
+../../../spine-cpp/src/spine

spine-ios/Sources/SpineC/spine-c

@@ -0,0 +1 @@
+../../../spine-c/src