Promote loongarch64-unknown-none* to Tier 2

MCP: rust-lang/compiler-team#664

Author: heiher

src/ci/docker/host-x86_64/dist-various-2/Dockerfile

@@ -124,6 +124,8 @@ ENV TARGETS=$TARGETS,armv7-unknown-linux-gnueabi
 ENV TARGETS=$TARGETS,armv7-unknown-linux-musleabi
 ENV TARGETS=$TARGETS,i686-unknown-freebsd
 ENV TARGETS=$TARGETS,x86_64-unknown-none
+ENV TARGETS=$TARGETS,loongarch64-unknown-none
+ENV TARGETS=$TARGETS,loongarch64-unknown-none-softfloat
 ENV TARGETS=$TARGETS,aarch64-unknown-uefi
 ENV TARGETS=$TARGETS,i686-unknown-uefi
 ENV TARGETS=$TARGETS,x86_64-unknown-uefi

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

@@ -153,6 +153,8 @@ target | std | notes
 `i686-unknown-freebsd` | ✓ | 32-bit FreeBSD
 `i686-unknown-linux-musl` | ✓ | 32-bit Linux with MUSL
 [`i686-unknown-uefi`](platform-support/unknown-uefi.md) | * | 32-bit UEFI
+[`loongarch64-unknown-none`](platform-support/loongarch-none.md) | * |  | LoongArch64 Bare-metal (LP64D ABI)
+[`loongarch64-unknown-none-softfloat`](platform-support/loongarch-none.md) | * |  | LoongArch64 Bare-metal (LP64S ABI)
 `mips-unknown-linux-musl` | ✓ | MIPS Linux with MUSL
 `mips64-unknown-linux-muslabi64` | ✓ | MIPS64 Linux, n64 ABI, MUSL
 `mips64el-unknown-linux-muslabi64` | ✓ | MIPS64 (LE) Linux, n64 ABI, MUSL

src/doc/rustc/src/platform-support/loongarch-none.md

@@ -1,6 +1,6 @@
 # `loongarch*-unknown-none*`
 
-**Tier: 3**
+**Tier: 2**
 
 Freestanding/bare-metal LoongArch64 binaries in ELF format: firmware, kernels, etc.
 

src/tools/build-manifest/src/main.rs

@@ -99,6 +99,8 @@ static TARGETS: &[&str] = &[
     "i686-unknown-linux-musl",
     "i686-unknown-uefi",
     "loongarch64-unknown-linux-gnu",
+    "loongarch64-unknown-none",
+    "loongarch64-unknown-none-softfloat",
     "m68k-unknown-linux-gnu",
     "mips-unknown-linux-gnu",
     "mips-unknown-linux-musl",