Specify 'simulator' environment explicitly

Clang understands `simulator` as a [valid environment](https://github.com/llvm/llvm-project/blob/657adcb0779d2d119737f2ca557a87456024a5ac/llvm/include/llvm/ADT/Triple.h#L231)
like `macabi` for Catalyst builds. It makes explicit
that the build is targeted at the Simulator. Otherwise,
`arm64-apple-ios11.0` is an iOS build which it tries to
link to the iPhoneSimulator SDK.

ios.toolchain.cmake

@@ -317,26 +317,26 @@ elseif(PLATFORM_INT STREQUAL "SIMULATOR")
   set(SDK_NAME iphonesimulator)
   if(NOT ARCHS)
     set(ARCHS i386)
-    set(APPLE_TARGET_TRIPLE_INT i386-apple-ios${DEPLOYMENT_TARGET})
+    set(APPLE_TARGET_TRIPLE_INT i386-apple-ios${DEPLOYMENT_TARGET}-simulator)
   else()
-    set(APPLE_TARGET_TRIPLE_INT ${ARCHS_SPLIT}-apple-ios${DEPLOYMENT_TARGET})
+    set(APPLE_TARGET_TRIPLE_INT ${ARCHS_SPLIT}-apple-ios${DEPLOYMENT_TARGET}-simulator)
   endif()
   message(DEPRECATION "SIMULATOR IS DEPRECATED. Consider using SIMULATOR64 instead.")
 elseif(PLATFORM_INT STREQUAL "SIMULATOR64")
   set(SDK_NAME iphonesimulator)
   if(NOT ARCHS)
     set(ARCHS x86_64)
-    set(APPLE_TARGET_TRIPLE_INT x86_64-apple-ios${DEPLOYMENT_TARGET})
+    set(APPLE_TARGET_TRIPLE_INT x86_64-apple-ios${DEPLOYMENT_TARGET}-simulator)
   else()
-    set(APPLE_TARGET_TRIPLE_INT ${ARCHS_SPLIT}-apple-ios${DEPLOYMENT_TARGET})
+    set(APPLE_TARGET_TRIPLE_INT ${ARCHS_SPLIT}-apple-ios${DEPLOYMENT_TARGET}-simulator)
   endif()
 elseif(PLATFORM_INT STREQUAL "SIMULATORARM64")
   set(SDK_NAME iphonesimulator)
   if(NOT ARCHS)
     set(ARCHS arm64)
-    set(APPLE_TARGET_TRIPLE_INT arm64-apple-ios${DEPLOYMENT_TARGET})
+    set(APPLE_TARGET_TRIPLE_INT arm64-apple-ios${DEPLOYMENT_TARGET}-simulator)
   else()
-    set(APPLE_TARGET_TRIPLE_INT ${ARCHS_SPLIT}-apple-ios${DEPLOYMENT_TARGET})
+    set(APPLE_TARGET_TRIPLE_INT ${ARCHS_SPLIT}-apple-ios${DEPLOYMENT_TARGET}-simulator)
   endif()
 elseif(PLATFORM_INT STREQUAL "TVOS")
   set(SDK_NAME appletvos)
@@ -366,9 +366,9 @@ elseif(PLATFORM_INT STREQUAL "SIMULATOR_TVOS")
   set(SDK_NAME appletvsimulator)
   if(NOT ARCHS)
     set(ARCHS x86_64)
-    set(APPLE_TARGET_TRIPLE_INT x86_64-apple-tvos${DEPLOYMENT_TARGET})
+    set(APPLE_TARGET_TRIPLE_INT x86_64-apple-tvos${DEPLOYMENT_TARGET}-simulator)
   else()
-    set(APPLE_TARGET_TRIPLE_INT ${ARCHS_SPLIT}-apple-tvos${DEPLOYMENT_TARGET})
+    set(APPLE_TARGET_TRIPLE_INT ${ARCHS_SPLIT}-apple-tvos${DEPLOYMENT_TARGET}-simulator)
   endif()
 elseif(PLATFORM_INT STREQUAL "WATCHOS")
   set(SDK_NAME watchos)
@@ -412,9 +412,9 @@ elseif(PLATFORM_INT STREQUAL "SIMULATOR_WATCHOS")
   set(SDK_NAME watchsimulator)
   if(NOT ARCHS)
     set(ARCHS i386)
-    set(APPLE_TARGET_TRIPLE_INT i386-apple-watchos${DEPLOYMENT_TARGET})
+    set(APPLE_TARGET_TRIPLE_INT i386-apple-watchos${DEPLOYMENT_TARGET}-simulator)
   else()
-    set(APPLE_TARGET_TRIPLE_INT ${ARCHS_SPLIT}-apple-watchos${DEPLOYMENT_TARGET})
+    set(APPLE_TARGET_TRIPLE_INT ${ARCHS_SPLIT}-apple-watchos${DEPLOYMENT_TARGET}-simulator)
   endif()
 elseif(PLATFORM_INT STREQUAL "MAC" OR PLATFORM_INT STREQUAL "MAC_CATALYST")
   set(SDK_NAME macosx)