rustc: remove riscv32i support

compilers/rustc-riscv32i.patch

@@ -1,67 +0,0 @@
-commit 23c32a1597df69083f4fa6fb932410cb342e266e
-Author: Sebastien Bourdeauducq <sb@m-labs.hk>
-Date:   Tue Apr 9 00:15:31 2019 +0800
-
-    add riscv32i
-
-diff --git a/src/librustc_target/spec/mod.rs b/src/librustc_target/spec/mod.rs
-index 46fefd78f4..181342db7d 100644
---- a/src/librustc_target/spec/mod.rs
-+++ b/src/librustc_target/spec/mod.rs
-@@ -465,6 +465,7 @@ supported_targets! {
-     ("aarch64-unknown-hermit", aarch64_unknown_hermit),
-     ("x86_64-unknown-hermit", x86_64_unknown_hermit),
- 
-+    ("riscv32i-unknown-none-elf", riscv32i_unknown_none_elf),
-     ("riscv32imc-unknown-none-elf", riscv32imc_unknown_none_elf),
-     ("riscv32imac-unknown-none-elf", riscv32imac_unknown_none_elf),
-     ("riscv64imac-unknown-none-elf", riscv64imac_unknown_none_elf),
-diff --git a/src/librustc_target/spec/riscv32i_unknown_none_elf.rs b/src/librustc_target/spec/riscv32i_unknown_none_elf.rs
-new file mode 100644
-index 0000000000..a015e16d93
---- /dev/null
-+++ b/src/librustc_target/spec/riscv32i_unknown_none_elf.rs
-@@ -0,0 +1,31 @@
-+use crate::spec::{LinkerFlavor, LldFlavor, PanicStrategy,
-+           Target, TargetOptions, TargetResult};
-+
-+pub fn target() -> TargetResult {
-+    Ok(Target {
-+        data_layout: "e-m:e-p:32:32-i64:64-n32-S128".to_string(),
-+        llvm_target: "riscv32".to_string(),
-+        target_endian: "little".to_string(),
-+        target_pointer_width: "32".to_string(),
-+        target_c_int_width: "32".to_string(),
-+        target_os: "none".to_string(),
-+        target_env: String::new(),
-+        target_vendor: "unknown".to_string(),
-+        arch: "riscv32".to_string(),
-+        linker_flavor: LinkerFlavor::Lld(LldFlavor::Ld),
-+
-+        options: TargetOptions {
-+            linker: Some("rust-lld".to_string()),
-+            cpu: "generic-rv32".to_string(),
-+            max_atomic_width: Some(32),
-+            atomic_cas: true,
-+            features: "-m,-a,-c".to_string(),
-+            executables: true,
-+            panic_strategy: PanicStrategy::Abort,
-+            relocation_model: "static".to_string(),
-+            emit_debug_gdb_scripts: false,
-+            abi_blacklist: super::riscv_base::abi_blacklist(),
-+            .. Default::default()
-+        },
-+    })
-+}
-diff --git a/src/tools/build-manifest/src/main.rs b/src/tools/build-manifest/src/main.rs
-index 61cc78ad80..4364ef41f9 100644
---- a/src/tools/build-manifest/src/main.rs
-+++ b/src/tools/build-manifest/src/main.rs
-@@ -92,6 +92,7 @@ static TARGETS: &[&str] = &[
-     "powerpc-unknown-linux-gnu",
-     "powerpc64-unknown-linux-gnu",
-     "powerpc64le-unknown-linux-gnu",
-+    "riscv32i-unknown-none-elf",
-     "riscv32imc-unknown-none-elf",
-     "riscv32imac-unknown-none-elf",
-     "riscv64imac-unknown-none-elf",

derivations.nix

@@ -22,7 +22,6 @@ rec {
   });
   rustc = (pkgs.rustc.overrideAttrs(oa: {
     name = "${oa.pname}-${oa.version}-riscv";
-    patches = oa.patches ++ [ ./compilers/rustc-riscv32i.patch ];
     configureFlags = oa.configureFlags ++ [ "--enable-lld" ];
   })).override {
     inherit llvm_7;