This reverts commit 42eb7db188f23625872b6f1d722979a3100d170e. This
reland 3fbb037d03e7ff1ef1cd9156363e895af7caaf98 (#209922).
Under CMake 4+, calling add_library(... SHARED IMPORTED) on a target
platform that lacks dynamic linking support triggers a fatal error. This
becomes an issue when building LLVM and runtimes for baremetal targets
like armv6m-none-eabi. This patch adds the option
"LLVM_OMIT_EXPORTS_FROM_CONFIG" in LLVM. When used in sub builds like
LLVM runtimes, it makes CMake to skip including the LLVM and Clang
exports. This mitigates the CMake 4 errors on baremetal runtimes.
42eb7db188f23625872b6f1d722979a3100d170e originally
apply this flag on all runtimes build and causing issues on runtimes
like intel-sycl-gpu, amdgpu-offload-ubuntu-22-cmake-build-only.
This PR only set this flag when the target platform lacks shared library
support.
(cherry picked from a04f87fdd9b59c6089bf731c669c6f149208363c and
91406e8dff2b1578ff4dd22593ea1a8039b074a4)
Haowei
1fee366f08