Function LLVMBuildFCmp 

#[unsafe(no_mangle)]
pub extern "C" fn LLVMBuildFCmp(
    arg1: LLVMBuilderRef,
    Op: LLVMRealPredicate,
    LHS: LLVMValueRef,
    RHS: LLVMValueRef,
    Name: *const c_char,
) -> LLVMValueRef