build: remove stdio.h from header checks #26150

1. 
   fanquake commented at 4:05 PM on September 21, 2022: member

   We already use a mix of <cstdio> and stdio.h unconditionally throughout the codebase.

   Us checking this header also duplicates work already done by autotools. Currently stdio.h is checked for 3 times during a ./configure run, after this change, at least it's only twice.

2. refactor: use <cstdio> over stdio.h

   We currently use both. Consolidate on the former.

   b95633121b
3. build: remove stdio.h from header checks

   We already use a mix of <cstdio> and stdio.h unconditionally throughout
   the codebase.
   
   Us checking this header also duplicates work already done by autotools.
   Currently stdio.h is checked for 3 times during a ./configure run, after
   this change, at least it's only twice.

   55aad5f3a9
4. fanquake added the label Build system on Sep 21, 2022
5. fanquake requested review from TheCharlatan on Sep 21, 2022
6. kristapsk approved
7. 
   kristapsk commented at 8:26 PM on September 21, 2022: contributor

   ACK 55aad5f3a957296776cfd8d7a4a251361355b8e8

8. 
   TheCharlatan commented at 11:16 AM on September 22, 2022: contributor

   ACK 55aad5f3a957296776cfd8d7a4a251361355b8e8

9. fanquake merged this on Sep 22, 2022
10. fanquake closed this on Sep 22, 2022

    ---

11. fanquake deleted the branch on Sep 22, 2022
12. sidhujag referenced this in commit fd278e9de1 on Sep 23, 2022
13. MarcoFalke referenced this in commit ec13810a00 on Sep 25, 2022
14. bitcoin locked this on Sep 22, 2023

Review Requested
TheCharlatan