These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.61 s (backtrack: 0/20).

[ebuild  NS    ] llvm-core/llvm-21.1.8:21/21.1::gentoo [22.1.1:22/22.1::gentoo] USE="binutils-plugin libffi zstd -debug (-debuginfod) -doc -exegesis -libedit -test -verify-sig -xml -z3" LLVM_TARGETS="(AArch64) (AMDGPU) (ARM) (AVR) (BPF) (Hexagon) (Lanai) (LoongArch) (MSP430) (Mips) (NVPTX) (PowerPC) (RISCV) (SPIRV) (Sparc) (SystemZ) (VE) (WebAssembly) (X86) (XCore) -ARC -CSKY -DirectX -M68k -Xtensa" 155530 KiB
[ebuild  NS    ] llvm-core/llvm-toolchain-symlinks-21:21::gentoo [22:22::gentoo] USE="-multilib-symlinks -native-symlinks" 0 KiB

Total: 2 packages (2 in new slots), Size of downloads: 155530 KiB