Auto merge of #114332 - nbdd0121:riscv, r=compiler-errors

Fix ABI flags in RISC-V/LoongArch ELF file generated by rustc

Fix #114153

It turns out the current way to set these flags are completely wrong. In LLVM the target ABI is used instead of target features to determine these flags.

Not sure how to write a test though. Or maybe a test isn't necessary because this affects only those touching target json?

r? `@Nilstrieb`

compiler/rustc_span/src/symbol.rs

@@ -445,6 +445,7 @@ symbols! {
         bridge,
         bswap,
         builtin_syntax,
+        c,
         c_str,
         c_str_literals,
         c_unwind,