[JDK-8294941](https://bugs.openjdk.org/browse/JDK-8294941) cut out some unused files in GHA sysroots. But I notice that even after that, we still have quite a bit of fluff there, especially in RISC-V sysroot. We can cut a bit deeper. Notably, we don't need runnable gcc in the sysroot, because we use the cross-compilation toolchain from the host.
This further saves bandwidth, cache size, etc. for actively developed projects. Seeing the following improvements in sysroot sizes: ARM: 64 MB -> 37 MB AArch64: 80 MB -> 46 MB S390X: 69 MB -> 41 MB PPC64: 84 MB -> 51 MB RISC-V: 287 MB -> 53 MB Total: 584 MB -> 228 MB (-61%) Additional testing: - [x] GHA (cross-builds still work fine) ------------- Commit messages: - Correction: libexec/gcc should be removed explicitly - Fix Changes: https://git.openjdk.org/jdk/pull/15287/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=15287&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8314262 Stats: 2 lines in 1 file changed: 1 ins; 0 del; 1 mod Patch: https://git.openjdk.org/jdk/pull/15287.diff Fetch: git fetch https://git.openjdk.org/jdk.git pull/15287/head:pull/15287 PR: https://git.openjdk.org/jdk/pull/15287
