Android: Use unified toolchain in NDK r19+

The NDK build system now uses only a single toolchain in

    <ndk>/toolchains/llvm/prebuilt/<host>

Its compilers are always `bin/{clang,clang++}` and its binutils are
always `bin/<triple>-*`.  It is a standalone toolchain:

* The Anrdoid API level is specified at the end of `--target=`.
* The standard library may be specified via `-stdlib=`.
* No need to pass system includes or libraries explicitly.
* No need to pass `--sysroot` or `-gcc-toolchain`.

Teach CMake to recognize NDK versions that have a unified
toolchain with its own sysroot and use the above approach.

Fixes: #18739

1 files changed, 3 insertions, 2 deletions

diff --git a/Tests/RunCMake/Android/ndk-badver-stderr.txt b/Tests/RunCMake/Android/ndk-badver-stderr.txt
index df2c5e6..ce6bc4e 100644
--- a/Tests/RunCMake/Android/ndk-badver-stderr.txt
+++ b/Tests/RunCMake/Android/ndk-badver-stderr.txt
@@ -1,11 +1,12 @@
 ^CMake Error at .*/Modules/Platform/Android/Determine-Compiler-NDK.cmake:[0-9]+ \(message\):
-  Android: The CMAKE_ANDROID_NDK_TOOLCHAIN_VERSION value 'badver' is not one
+  Android: The CMAKE_ANDROID_NDK_TOOLCHAIN_VERSION value 'badver' is not(
+  supported by this NDK.  It must be 'clang' or not set at all\.| one
   of the allowed forms:
 
     <major>.<minor>       = GCC of specified version
     clang<major>.<minor>  = Clang of specified version
     clang                 = Clang of most recent available version
-
+)
 Call Stack \(most recent call first\):
 .*
   ndk-badver.cmake:1 \(enable_language\)