Possible upstream rustc support for qoriq ppcspe arch

[th0ma7]

Note to @SynoCommunity/developers as there may be upstream support now available for ppcspe platform such as qoriq.

Recent merged PR: rust-lang/rust#137860 (comment)
Upstream bug entered by @th0ma7 : rust-lang/rust#117361

[hgy59]

I dnon't know whether the recent errror error: invalid value '1.82.0-powerpc-unknown-linux-gnuspe' for '<TOOLCHAIN>': invalid custom toolchain name '1.82.0-powerpc-unknown-linux-gnuspe' is related to this.

@th0ma7 I guess we have to drop rust support for qoriq in spksrc framework.

Tried to build custom rust toolchain for 1.82.0-powerpc-unknown-linux-gnuspe but it failed to create compiler_builtins...

   Compiling shlex v1.3.0
   Compiling core v0.0.0 (/spksrc/toolchain/syno-qoriq-6.2.4/work/rust/library/core)
   Compiling libc v0.2.169
   Compiling object v0.36.7
   Compiling cc v1.2.0
   Compiling std v0.0.0 (/spksrc/toolchain/syno-qoriq-6.2.4/work/rust/library/std)
   Compiling compiler_builtins v0.1.140
warning: [email protected]: In file included from /spksrc/toolchain/syno-qoriq-6.2.4/work/rust/src/llvm-project/compiler-rt/lib/builtins/divdc3.c:14:0:
warning: [email protected]: /spksrc/toolchain/syno-qoriq-6.2.4/work/rust/src/llvm-project/compiler-rt/lib/builtins/fp_lib.h: In function '__compiler_rt_scalbnX':
warning: [email protected]: /spksrc/toolchain/syno-qoriq-6.2.4/work/rust/src/llvm-project/compiler-rt/lib/builtins/fp_lib.h:305:3: error: implicit declaration of function '__builtin_sadd_overflow' [-Werror=implicit-function-declaration]
warning: [email protected]:    if (__builtin_sadd_overflow(exp, y, &exp)) {
warning: [email protected]:    ^
warning: [email protected]: /spksrc/toolchain/syno-qoriq-6.2.4/work/rust/src/llvm-project/compiler-rt/lib/builtins/divdc3.c: At top level:
warning: [email protected]: /spksrc/toolchain/syno-qoriq-6.2.4/work/rust/src/llvm-project/compiler-rt/lib/builtins/divdc3.c:20:26: warning: conflicting types for built-in function '__divdc3'
warning: [email protected]:  COMPILER_RT_ABI Dcomplex __divdc3(double __a, double __b, double __c,
warning: [email protected]:                           ^
warning: [email protected]: cc1: some warnings being treated as errors
error: failed to run custom build command for `compiler_builtins v0.1.140`

Caused by:
  process didn't exit successfully: `/spksrc/toolchain/syno-qoriq-6.2.4/work/rust/build/x86_64-unknown-linux-gnu/stage2-std/release/build/compiler_builtins-7bc622120e7aa6e4/build-script-build` (exit status: 1)

.....

warning: build failed, waiting for other jobs to finish...
Build completed unsuccessfully in 0:22:41
make: *** [../../mk/spksrc.tc-rust.mk:104: rustc_target] Error 1