pub unsafe extern "C" fn LLVMRustCoverageWriteMappingToBuffer(
    VirtualFileMappingIDs: *const c_uint,
    NumVirtualFileMappingIDs: c_uint,
    Expressions: *const CounterExpression,
    NumExpressions: c_uint,
    MappingRegions: *const CounterMappingRegion,
    NumMappingRegions: c_uint,
    BufferOut: &RustString
)