Add temporary config files and settings for RISC-V development

.cargo/config.toml

@@ -0,0 +1,16 @@
+[env]
+CC_riscv64gc-unknown-linux-gnu = "clang-17 --target=riscv64-unknown-linux-gnu -march=rv64gcv1p0 -fuse-ld=lld-17"
+CXX_riscv64gc-unknown-linux-gnu = "clang++-17 --target=riscv64-unknown-linux-gnu -march=rv64gcv1p0 -fuse-ld=lld-17"
+
+[build]
+target = "riscv64gc-unknown-linux-gnu"
+
+[target.riscv64gc-unknown-linux-gnu]
+runner = "qemu-riscv64 -cpu rv64,v=true,vext_spec=v1.0"
+linker = "clang-17"
+rustflags = [
+  "-C", "link-arg=-fuse-ld=lld-17",
+  "-C", "link-arg=-march=rv64gcv1p0",
+  "-C", "link-arg=--target=riscv64-unknown-linux-gnu",
+  "-C", "target-feature=+v",
+]

c/.clangd

@@ -0,0 +1,12 @@
+Diagnostics:
+  Suppress:
+    - -Wimplicit-function-declaration
+    - fatal_too_many_errors
+    - typecheck_convert_incompatible
+    - undeclared_var_use
+  UnusedIncludes: None
+InlayHints:
+  Designators: Yes
+  Enabled: Yes
+  ParameterNames: Yes
+  DeducedTypes: Yes

c/CMakeLists.txt

@@ -1,5 +1,20 @@
 cmake_minimum_required(VERSION 3.9 FATAL_ERROR)
 
+set(CMAKE_GENERATOR Ninja)
+set(CMAKE_BUILD_TYPE Release)
+set(CMAKE_SYSTEM_NAME Linux)
+set(CMAKE_CROSSCOMPILING_EMULATOR qemu-riscv64-static)
+set(CMAKE_ASM_COMPILER clang-17)
+set(CMAKE_ASM_COMPILER_TARGET riscv64-unknown-linux-gnu)
+set(CMAKE_ASM_FLAGS_INIT "-march=rv64gcv1p0")
+set(CMAKE_C_COMPILER clang-17)
+set(CMAKE_C_COMPILER_TARGET riscv64-unknown-linux-gnu)
+set(CMAKE_C_FLAGS_INIT "-march=rv64gcv1p0")
+set(CMAKE_CXX_COMPILER clang++-17)
+set(CMAKE_CXX_COMPILER_TARGET riscv64-unknown-linux-gnu)
+set(CMAKE_CXX_FLAGS_INIT "-march=rv64gcv1p0")
+set(CMAKE_EXE_LINKER_FLAGS "-fuse-ld=lld-17")
+
 # respect C_EXTENSIONS OFF without explicitly setting C_STANDARD
 if (POLICY CMP0128)
   cmake_policy(SET CMP0128 NEW)