[clang][driver] Set TLSDESC as the default for Android on RISC-V (#81198)

Author: ilovepi

clang/test/Driver/tls-dialect.c

@@ -3,6 +3,10 @@
 // RUN: %clang -### --target=riscv64-linux %s 2>&1 | FileCheck --check-prefix=NODESC %s
 // RUN: %clang -### --target=x86_64-linux -mtls-dialect=gnu %s 2>&1 | FileCheck --check-prefix=NODESC %s
 
+/// Android supports TLSDESC by default on RISC-V
+/// TLSDESC is not on by default in Linux, even on RISC-V, and is covered above
+// RUN: %clang -### --target=riscv64-android %s 2>&1 | FileCheck --check-prefix=DESC %s
+
 /// LTO
 // RUN: %clang -### --target=riscv64-linux -flto -mtls-dialect=desc %s 2>&1 | FileCheck --check-prefix=LTO-DESC %s
 // RUN: %clang -### --target=riscv64-linux -flto %s 2>&1 | FileCheck --check-prefix=LTO-NODESC %s

llvm/include/llvm/TargetParser/Triple.h

@@ -1035,10 +1035,7 @@ class Triple {
 
   /// True if the target supports both general-dynamic and TLSDESC, and TLSDESC
   /// is enabled by default.
-  bool hasDefaultTLSDESC() const {
-    // TODO: Improve check for other platforms, like Android, and RISC-V
-    return false;
-  }
+  bool hasDefaultTLSDESC() const { return isAndroid() && isRISCV64(); }
 
   /// Tests whether the target uses -data-sections as default.
   bool hasDefaultDataSections() const {