Rollup merge of #116618 - chriswailes:riscv64-linux-android-vector, r=workingjubilee

Add the V (vector) extension to the riscv64-linux-android target spec

This feature has been enabled and tested internally in the Android project.

compiler/rustc_target/src/spec/riscv64_linux_android.rs

@@ -9,7 +9,7 @@ pub fn target() -> Target {
         options: TargetOptions {
             code_model: Some(CodeModel::Medium),
             cpu: "generic-rv64".into(),
-            features: "+m,+a,+f,+d,+c,+Zba,+Zbb,+Zbs".into(),
+            features: "+m,+a,+f,+d,+c,+zba,+zbb,+zbs,+v".into(),
             llvm_abiname: "lp64d".into(),
             supported_sanitizers: SanitizerSet::ADDRESS,
             max_atomic_width: Some(64),

src/doc/rustc/src/platform-support/android.md

@@ -45,3 +45,19 @@ The riscv64-linux-android target is supported as a Tier 3 target.
 
 A list of all supported targets can be found
 [here](../platform-support.html)
+
+## Architecture Notes
+
+### riscv64-linux-android
+
+Currently the `riscv64-linux-android` target requires the following architecture features/extensions:
+
+* `a` (atomics)
+* `d` (double-precision floating-point)
+* `c` (compressed instruction set)
+* `f` (single-precision floating-point)
+* `m` (multiplication and division)
+* `v` (vector)
+* `Zba` (address calculation instructions)
+* `Zbb` (base instructions)
+* `Zbs` (single-bit instructions)