Merge pull request #10176 from orezraey/docs/libc-memmem-memccpy-exports

docs(libc): record that libSceLibcInternal does not export memmem or memccpy

docs/dev/debt/libc.md

@@ -80,7 +80,7 @@
 - [_Divide, _FDivide, _Recip and _FRecip](../../../core/libs/prx/libc/src/DinkumwareInternals.cpp) (libc) follow the Dinkumware CRT division and reciprocal contracts with IEEE-754 signed-zero, infinity and NaN behavior. The exact console results, signaling-NaN handling and floating-point exception behavior are not verified.
 
 - [sscanf_s and vsscanf_s](../../../core/libs/prx/libc/src/Formatting.cpp) (libc) return `EOF` when a reached conversion has a null destination, stopping before further assignments, following C11 K.3.5.3.7 and K.3.5.3.14. Earlier assignments are retained. The constraint handler is not invoked, and console behaviour is unverified.
-- [memmem and memccpy](../../../core/libs/prx/libc/src/Strings.cpp) (libc) - `memmem` searches for needle occurrences in memory buffers and `memccpy` copies buffers until a character match, following FreeBSD and POSIX specifications; behavior is unverified on console.
+- [memmem and memccpy](../../../core/libs/prx/libc/src/Strings.cpp) (libc) - `memmem` searches for needle occurrences in memory buffers and `memccpy` copies buffers until a character match, following FreeBSD and POSIX specifications; behavior is unverified on console. Neither is exported by `libSceLibcInternal.sprx` on a PS5 (firmware 13.60), so a payload process cannot call them there.
 - [strtof and wcstof](../../../core/libs/prx/libc/src/Strings.cpp) (libc) round to the nearest float, where the console's `_Stof` in `libSceLibcInternal.sprx` (0x734a0) does not always: about a third of decimal inputs within a relative 2^-51 of a point halfway between two floats, and some hexadecimal inputs with more than 24 significant bits, come out one unit apart in the last place (`1e-40` is `0x1.16c3p-133` there and `0x1.16c2p-133` here). The console's own rounding is not reproduced
 - [strtof and wcstof](../../../core/libs/prx/libc/src/Strings.cpp) (libc) - `ERANGE` follows the `libc.prx` bundled with PPSA08427 (J03547016) and PPSA03671 (J03848509), both run side by side with this libc on a Linux host: a decimal input whose result is a nonzero subnormal sets it only when inexact, a hexadecimal one only when it lies below the smallest subnormal and rounds up to it, and underflow to zero and overflow set it. Both builds also take a `NAN(...)` payload in `strtof` from the sequence's leading digits (`nan(0x123)` is `0x7fc00123`, `-nan(5)` is `0xffc00005`); the sign is kept here, the payload is not. `libSceLibcInternal`'s `_Stof` differs: no `ERANGE` for hexadecimal input, a positive `nan`, and after a minus sign a failed parse is `-0.0` for a lone sign and `+0.0` before an `inf`/`nan` spelling, the reverse of `libc.prx`. Decimal `strtod` sets `ERANGE` for a nonzero subnormal in J03547016 but not in J03848509 or `libSceLibcInternal`, whose result is kept.