Update LoongArch builds for latest developments

[nathanchance]

CONFIG_RELOCATABLE has been fixed since 6.7 with two changes (the first one fixes the build and the second one fixes boot):

aa0cbc1b506b ("LoongArch: Record pc instead of offset in la_abs relocation")
eea673e9d5ea ("LoongArch: Apply dynamic relocations for LLD")

Re-enable CONFIG_RELOCATABLE (removing CONFIG_CRASH_DUMP=n as well, as it was only disabled to allow CONFIG_RELOCATABLE to be disabled) for all trees. eea673e9d5ea has been flagged by AUTOSEL for 6.6 but it has not been added to the tree yet, so just apply it locally for the time being.

The minimum supported version of clang for LoongArch has been updated to 18.0.0 in -next with commit 4d35d6e56447 ("scripts/min-tool-version.sh: Raise minimum clang version to 18.0.0 for loongarch") because it is the first version that supports __attribute__((model("extreme"))), which allows us to build with CONFIG_MODULES.

In order to support CONFIG_MODULES unconditionally (i.e., not disable it at all), we must drop support for clang-17 everywhere. We already have to do it for -next (and eventually mainline) due to the aforementioned commit. Do so, which helps drastically simplify the matrix.

Because CONFIG_MODULES does not need to be disabled anymore, we can build allmodconfig instead of allyesconfig, which also allows us to stop disabling CONFIG_KCOV because the image size is much smaller.

I am testing this locally with scripts/build-local.py, I plan to merge it once this pull is approved and those tests pass.

[nathanchance]

loongarch.yml

jobs:
- name: loongarch
  builds:
  - target_arch: loongarch
    toolchain: clang-nightly
    kconfig: defconfig
    targets:
    - kernel
    make_variables:
      LLVM: 1
      LLVM_IAS: 1
  - target_arch: loongarch
    toolchain: clang-nightly
    kconfig:
    - defconfig
    - CONFIG_LTO_CLANG_THIN=y
    targets:
    - kernel
    make_variables:
      LLVM: 1
      LLVM_IAS: 1
  - target_arch: loongarch
    toolchain: clang-nightly
    kconfig:
    - allmodconfig
    - CONFIG_WERROR=n
    targets:
    - default
    make_variables:
      LLVM: 1
      LLVM_IAS: 1
  - target_arch: loongarch
    toolchain: clang-nightly
    kconfig:
    - allmodconfig
    - CONFIG_FTRACE=n
    - CONFIG_GCOV_KERNEL=n
    - CONFIG_LTO_CLANG_THIN=y
    - CONFIG_WERROR=n
    targets:
    - default
    make_variables:
      LLVM: 1
      LLVM_IAS: 1

passes -next, mainline, linux-6.7.y, and linux-6.6.y for me locally. I had to add CONFIG_WERROR=n to workaround ClangBuiltLinux/linux#1966 (which is not a LoongArch specific problem anyways). If that is not dealt with relatively quickly, we can apply Kees's suggested workaround to get things back to green relatively quickly.

[nathanchance]

The patch I am adding in this pull request is out for review: https://lore.kernel.org/all/20240118104323.024232838@linuxfoundation.org/

I will rebase and merge this once that patch is in a released version, so that we do not have to worry about the patch failing to apply.

[nathanchance]

Alright, this should be ready to go.