`registerImplicitTypeID` conflicts with dynlib on `x86_64-pc-windows-gnullvm`

[SchrodingerZhu]

llvm-project/mlir/include/mlir/Support/TypeID.h

Line 167 in 9b7fd00

LLVM_ALWAYS_EXPORT static TypeID registerImplicitTypeID(StringRef name);

Consider libX being a DLL built with MLIR.
Binary A links against both MLIR's libraries and libX.

With x86_64-pc-windows-gnullvm this leads to duplicated symbols even when libX is compiled with visibility hidden as registerImplicitTypeID is forcibly marked as exported.

[llvmbot]

@llvm/issue-subscribers-mlir

Author: Schrodinger ZHU Yifan (SchrodingerZhu)

https://github.com/llvm/llvm-project/blob/9b7fd0099e79b0f5b824027cbae8a25356486ac9/mlir/include/mlir/Support/TypeID.h#L167

Consider libX being a DLL built with MLIR.
Binary A links against both MLIR's libraries and libX.

With x86_64-pc-windows-gnullvm this leads to duplicated symbols even when libX is compiled with visibility hidden as registerImplicitTypeID is forcibly marked as exported.

[SchrodingerZhu]

Should this be a weak_odr or selectany symbol?