Restore hexagon architecture support (#172)

Use the nightly toolchain to verify the hexagon functionality since it's
not normally built.

Author: androm3da

.github/workflows/main.yml

@@ -65,6 +65,10 @@ jobs:
     - run: cargo check --tests -vv --target=powerpc64le-unknown-linux-gnu
     - run: cargo check --tests -vv --target=armv5te-unknown-linux-gnueabi
     - run: cargo check --tests -vv --target=loongarch64-unknown-linux-gnu
+    - run : >
+        rustup component add rust-src --toolchain nightly-x86_64-unknown-linux-gnu &&
+        cargo +nightly check --tests -vv --target=hexagon-unknown-linux-musl -Zbuild-std -Zbuild-std-features=llvm-libunwind 
+
 
   gen:
     name: Update generated files

gen/src/main.rs

@@ -289,8 +289,7 @@ fn rust_arches(linux_arch: &str) -> &[&str] {
         "arm64" => &["aarch64"],
         "avr32" => &["avr"],
         "csky" => &["csky"],
-        // hexagon gets build errors; disable it for now
-        "hexagon" => &[],
+        "hexagon" => &["hexagon"],
         "loongarch" => &["loongarch64"],
         "mips" => &["mips", "mips64", "mips32r6", "mips64r6"],
         "powerpc" => &["powerpc", "powerpc64"],

src/hexagon/auxvec.rs

@@ -0,0 +1,30 @@
+/* automatically generated by rust-bindgen 0.72.1 */
+
+pub const AT_NULL: u32 = 0;
+pub const AT_IGNORE: u32 = 1;
+pub const AT_EXECFD: u32 = 2;
+pub const AT_PHDR: u32 = 3;
+pub const AT_PHENT: u32 = 4;
+pub const AT_PHNUM: u32 = 5;
+pub const AT_PAGESZ: u32 = 6;
+pub const AT_BASE: u32 = 7;
+pub const AT_FLAGS: u32 = 8;
+pub const AT_ENTRY: u32 = 9;
+pub const AT_NOTELF: u32 = 10;
+pub const AT_UID: u32 = 11;
+pub const AT_EUID: u32 = 12;
+pub const AT_GID: u32 = 13;
+pub const AT_EGID: u32 = 14;
+pub const AT_PLATFORM: u32 = 15;
+pub const AT_HWCAP: u32 = 16;
+pub const AT_CLKTCK: u32 = 17;
+pub const AT_SECURE: u32 = 23;
+pub const AT_BASE_PLATFORM: u32 = 24;
+pub const AT_RANDOM: u32 = 25;
+pub const AT_HWCAP2: u32 = 26;
+pub const AT_RSEQ_FEATURE_SIZE: u32 = 27;
+pub const AT_RSEQ_ALIGN: u32 = 28;
+pub const AT_HWCAP3: u32 = 29;
+pub const AT_HWCAP4: u32 = 30;
+pub const AT_EXECFN: u32 = 31;
+pub const AT_MINSIGSTKSZ: u32 = 51;

src/hexagon/bootparam.rs

@@ -0,0 +1,3 @@
+/* automatically generated by rust-bindgen 0.72.1 */
+
+