Add definitions for riscv64_linux_android target

compiler/rustc_target/src/spec/mod.rs

@@ -1300,6 +1300,7 @@ supported_targets! {
     ("armv7-linux-androideabi", armv7_linux_androideabi),
     ("thumbv7neon-linux-androideabi", thumbv7neon_linux_androideabi),
     ("aarch64-linux-android", aarch64_linux_android),
+    ("riscv64-linux-android", riscv64_linux_android),
 
     ("aarch64-unknown-freebsd", aarch64_unknown_freebsd),
     ("armv6-unknown-freebsd", armv6_unknown_freebsd),

compiler/rustc_target/src/spec/riscv64_linux_android.rs

@@ -0,0 +1,19 @@
+use crate::spec::{CodeModel, SanitizerSet, Target, TargetOptions};
+
+pub fn target() -> Target {
+    Target {
+        llvm_target: "riscv64-linux-android".into(),
+        pointer_width: 64,
+        data_layout: "e-m:e-p:64:64-i64:64-i128:128-n32:64-S128".into(),
+        arch: "riscv64".into(),
+        options: TargetOptions {
+            code_model: Some(CodeModel::Medium),
+            cpu: "generic-rv64".into(),
+            features: "+m,+a,+f,+d,+c".into(),
+            llvm_abiname: "lp64d".into(),
+            supported_sanitizers: SanitizerSet::ADDRESS,
+            max_atomic_width: Some(64),
+            ..super::android_base::opts()
+        },
+    }
+}

library/std/src/os/android/raw.rs

@@ -89,7 +89,7 @@ mod arch {
     }
 }
 
-#[cfg(target_arch = "aarch64")]
+#[cfg(any(target_arch = "aarch64", target_arch = "riscv64"))]
 mod arch {
     use crate::os::raw::{c_int, c_long, c_uint, c_ulong};
     use crate::os::unix::raw::{gid_t, uid_t};

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

@@ -309,6 +309,7 @@ target | std | host | notes
 `riscv64gc-unknown-linux-musl` |   |   | RISC-V Linux (kernel 4.20, musl 1.2.0)
 [`riscv64gc-unknown-netbsd`](platform-support/netbsd.md) | ✓ | ✓ | RISC-V NetBSD
 [`riscv64gc-unknown-openbsd`](platform-support/openbsd.md) | ✓ | ✓ | OpenBSD/riscv64
+[`riscv64-linux-android`](platform-support/android.md) |   |   | RISC-V 64-bit Android
 `s390x-unknown-linux-musl` |  |  | S390x Linux (kernel 3.2, MUSL)
 `sparc-unknown-linux-gnu` | ✓ |  | 32-bit SPARC Linux
 [`sparc64-unknown-netbsd`](platform-support/netbsd.md) | ✓ | ✓ | NetBSD/sparc64