Reapply "[libc] printf, putchar and vprintf in bareemetal entrypoints (llvm#95436)"

This reverts commit eca988a.
The underlying libc issue was fixed by PR#95576.

Author: zeroomega

libc/config/baremetal/arm/entrypoints.txt

@@ -80,8 +80,11 @@ set(TARGET_LIBC_ENTRYPOINTS
 
     # stdio.h entrypoints
     libc.src.stdio.remove
+    libc.src.stdio.printf
+    libc.src.stdio.putchar
     libc.src.stdio.sprintf
     libc.src.stdio.snprintf
+    libc.src.stdio.vprintf
     libc.src.stdio.vsprintf
     libc.src.stdio.vsnprintf
 

libc/config/baremetal/riscv/entrypoints.txt

@@ -80,8 +80,11 @@ set(TARGET_LIBC_ENTRYPOINTS
 
     # stdio.h entrypoints
     libc.src.stdio.remove
+    libc.src.stdio.printf
+    libc.src.stdio.putchar
     libc.src.stdio.sprintf
     libc.src.stdio.snprintf
+    libc.src.stdio.vprintf
     libc.src.stdio.vsprintf
     libc.src.stdio.vsnprintf