Properly generate an android_ndk toolset

Generate a real ndk toolset instead of masquerading the ndk with a fake gcc prefix.

Diffs=
2018358a6 Properly generate an android_ndk toolset (#6506)

Co-authored-by: Chris Dalton <99840794+csmartdalton@users.noreply.github.com>

.rive_head

diff --git a/.rive_head b/.rive_head
index 8ed3cc4..f218173 100644
--- a/.rive_head
+++ b/.rive_head
@@ -1 +1 @@
-73bf11db39230e7a6d302da9a27414d35bcbee99
+2018358a6b7dc1dc1d6ca5ded14f11d4b3e072ca

build/setup_compiler.lua

diff --git a/build/setup_compiler.lua b/build/setup_compiler.lua
index 6a3c9c9..618ce39 100644
--- a/build/setup_compiler.lua
+++ b/build/setup_compiler.lua
@@ -155,7 +155,7 @@
 filter {"options:with-exceptions"} exceptionhandling "On"
 filter{}
 
--- Don't use filter() here because we don't want to generate the "ndk-redirect-*" files if not
+-- Don't use filter() here because we don't want to generate the "android_ndk" toolset if not
 -- building for android.
 if _OPTIONS["os"] == "android"
 then
@@ -173,55 +173,23 @@
         ndk_toolchain = ndk_toolchain .. "/linux-x86_64"
     end
 
-    -- Using "gcc" allows us to redirect the compiler to the (clang) NDK.
-    toolset "gcc"
-    gccprefix (_WORKING_DIR .. "/ndk-redirect-")
-
-    -- Masquerade the clang NDK as a "gcc" cross-compiler.
-    file = io.open(_WORKING_DIR .. "/ndk-redirect-g++", "w")
-    file:write("#!/bin/bash\n")
-    file:write(ndk_toolchain .. "/bin/clang++ $@")
-    file:close()
-    os.execute("chmod +x " .. _WORKING_DIR .. "/ndk-redirect-g++")
-
-    file = io.open(_WORKING_DIR .. "/ndk-redirect-gcc", "w")
-    file:write("#!/bin/bash\n")
-    file:write(ndk_toolchain .. "/bin/clang $@")
-    file:close()
-    os.execute("chmod +x " .. _WORKING_DIR .. "/ndk-redirect-gcc")
-
-    file = io.open(_WORKING_DIR .. "/ndk-redirect-ar", "w")
-    file:write("#!/bin/bash\n")
-    file:write(ndk_toolchain .. "/bin/llvm-ar $@")
-    file:close()
-    os.execute("chmod +x " .. _WORKING_DIR .. "/ndk-redirect-ar")
-
-    pic "on" -- Position-independent code is required for NDK libraries.
-    filter "options:arch=x86"
-    do
-        architecture "x86"
-        buildoptions {"--target=i686-none-linux-android23"}
-        linkoptions {"--target=i686-none-linux-android23"}
+    -- clone the clang toolset into a custom one called "android_ndk".
+    premake.tools.android_ndk = {}
+    for k,v in pairs(premake.tools.clang) do
+        premake.tools.android_ndk[k] = v
     end
-    filter "options:arch=x64"
-    do
-        architecture "x64"
-        buildoptions {"--target=x86_64-none-linux-android23"}
-        linkoptions {"--target=x86_64-none-linux-android23"}
+
+    -- update the android_ndk toolset to use the appropriate binaries.
+    local android_ndk_tools = {
+        cc = ndk_toolchain .. "/bin/clang",
+        cxx = ndk_toolchain .. "/bin/clang++",
+        ar = ndk_toolchain .. "/bin/llvm-ar"
+    }
+    function premake.tools.android_ndk.gettoolname(cfg, tool)
+        return android_ndk_tools[tool]
     end
-    filter "options:arch=arm"
-    do
-        architecture "arm"
-        buildoptions {"--target=armv7a-none-linux-android23"}
-        linkoptions {"--target=armv7a-none-linux-android23"}
-    end
-    filter "options:arch=arm64"
-    do
-        architecture "arm64"
-        buildoptions {"--target=aarch64-none-linux-android23"}
-        linkoptions {"--target=aarch64-none-linux-android23"}
-    end
-    filter {}
+
+    toolset "android_ndk"
 
     buildoptions {
         "--sysroot=" .. ndk_toolchain .. "/sysroot",
@@ -245,6 +213,33 @@
         "-Wl,--no-undefined",
         "-static-libstdc++",
     }
+
+    pic "on" -- Position-independent code is required for NDK libraries.
+    filter "options:arch=x86"
+    do
+        architecture "x86"
+        buildoptions {"--target=i686-none-linux-android21"}
+        linkoptions {"--target=i686-none-linux-android21"}
+    end
+    filter "options:arch=x64"
+    do
+        architecture "x64"
+        buildoptions {"--target=x86_64-none-linux-android21"}
+        linkoptions {"--target=x86_64-none-linux-android21"}
+    end
+    filter "options:arch=arm"
+    do
+        architecture "arm"
+        buildoptions {"--target=armv7a-none-linux-android21"}
+        linkoptions {"--target=armv7a-none-linux-android21"}
+    end
+    filter "options:arch=arm64"
+    do
+        architecture "arm64"
+        buildoptions {"--target=aarch64-none-linux-android21"}
+        linkoptions {"--target=aarch64-none-linux-android21"}
+    end
+    filter {}
 end
 
 newoption {