Rollup merge of #127967 - joshua-zivkovic:joshua-zivkovic/disable-split-debuginfo, r=jieyouxu

Disable run-make/split-debuginfo test for RISC-V 64

Together with `@Hoverbear,` we've been improving the state of the riscv64gc-unknown-linux-gnu target.

This is in relation to #125220 where `tests/ui/debuginfo/debuginfo-emit-llvm-ir-and-split-debuginfo.rs` was disabled for RISC-V 64 in that another test, `tests/run-make/split-debuginfo` also needs to be disabled due to llvm/llvm-project#56642 and the changes made in #120518.

This test appears to be a host test, not a target test, so it isn't seen failing in #126641, however, we are in the process of testing host tools for riscv64-gc-unknown-linux-gnu so this test has now been noticed to be a problem.

Author: matthiaskrgr

tests/run-make/split-debuginfo/Makefile

@@ -1,4 +1,6 @@
 # ignore-cross-compile
+# ignore-riscv64 On this platform only `-Csplit-debuginfo=off` is supported, see #120518
+
 include ../tools.mk
 
 all: off packed unpacked