fix(libc): accept the ' flag in Windows formatting

FreeBSD's vfprintf takes ' as the thousands-grouping flag. The Windows
formatter threw on it as an unsupported conversion. The guest's setlocale
only accepts the C locale, which has no thousands separator, so the flag
changes nothing: it is dropped before the host's printf sees it, and the
host's locale cannot add separators.

core/libs/prx/libc/include/WindowsFormatting.hpp

@@ -174,7 +174,8 @@ inline int FormatWindows(char* buffer, size_t size, const char* format, const vo
             continue;
         }
         std::string spec = "%";
-        while (*format && std::strchr("-+ #0", *format)) spec += *format++;
+        for (; *format && std::strchr("-+ #0'", *format); ++format)
+            if (*format != '\'') spec += *format;
         if (*format == '*') {
             ++format;
             const int width = args.Next<int>();

core/libs/tests/Formatting.cpp

@@ -126,6 +126,10 @@ __attribute__((noinline)) static void APS5_VABI RunChecks() {
     Require(std::strcmp(buffer, "1.0 2.0 3.0 4.0 5.0 6.0 7.0 8.0 9.0 10.0") == 0);
     snprintf_nid_postfix(buffer, sizeof(buffer), "%.3Lf %d %.1f", 1.125L, 7, 2.5);
     Require(std::strcmp(buffer, "1.125 7 2.5") == 0);
+    Require(snprintf_nid_postfix(buffer, sizeof(buffer), "%'d|%'u|%'.2f|%'-8ld|%'+05d|%'g", 1234567, 4000000000u, 1234567.891, 1234567LL, 42, 1e6) == 50);
+    Require(std::strcmp(buffer, "1234567|4000000000|1234567.89|1234567 |+0042|1e+06") == 0);
+    Require(FormatList(buffer, sizeof(buffer), "%'lld %'zu", 1234567890123LL, static_cast<std::size_t>(9876543210)) == 24 && std::strcmp(buffer, "1234567890123 9876543210") == 0);
+    Require(FormatList(buffer, sizeof(buffer), "%'d %ls", 1234567, u"x") == 9 && std::strcmp(buffer, "1234567 x") == 0);
     char expected[1024];
     std::snprintf(expected, sizeof(expected), "%#08x %.3e %a %g 0x%llx", 42u, 1.25, 1.25, 1.25,
         static_cast<unsigned long long>(reinterpret_cast<std::uintptr_t>(buffer)));

docs/dev/TechnicalDebt.md

@@ -549,7 +549,7 @@ Throughout the project, every function at every stage either **does exactly what
 - [Buffer loads without GLC or DLC](../../core/shader/recompiler/SpirvBackend/src/SpirvAnalysis.cpp) (shader recompiler) are not coherent in a program that has GLC or DLC buffer accesses and no `buffer_gl0_inv`, `buffer_gl1_inv`, `s_gl1_inv` or `s_dcache_inv`: only its GLC and DLC loads, stores and atomics use the `Coherent` buffer view, so a plain load can return a value cached before another work-group's write. This follows the [LLVM AMDGPU memory model for GFX10](https://llvm.org/docs/AMDGPUUsage.html#memory-model-gfx10-gfx11), in which a load-acquire is a GLC DLC load followed by `buffer_gl1_inv` and `buffer_gl0_inv`; it is not measured on the console or on RDNA hardware.
 - [DS src2 operations](../../core/shader/recompiler/Translation/src/MemoryInstructions/SharedMemoryInstructions.cpp) (`ds_*_src2_*`, GFX10.1 only) read `DS[B]`, with `B = A + 4 * sext(offset1[6:0]:offset0)`, and then update `DS[A]` with the matching 32-bit atomic, so the read of `B` is not atomic with the update of `A`. The form that takes the offset from the address (`offset1[7]` set), the 64-bit forms and GDS throw: whether the LDS address keeps `A[31:17]` in that form, and whether the 64-bit forms scale the offset by 4 or 8, is not documented. `ds_min_src2_f32`, `ds_max_src2_f32` and `ds_add_src2_f32` throw: on RDNA2 (gfx1035, the oracle's hardware, which has no src2 opcodes) `ds_min_f32`, `ds_max_f32` and `ds_add_f32` ignore `IEEE_MODE` but depend on whether f32 denormals are flushed (28, 28 and 12 of 196 special rows differ), and that is not modelled for LDS float atomics yet (#981).
 - [wcsrtombs_s](../../core/libs/prx/libc/src/Multibyte.cpp) (libc) follows the console's `libc.prx`, but a runtime-constraint violation only returns its error: the default handler there writes the message and a newline to `stderr` before returning, which is not done here. Conversion uses the C locale of `wcrtomb` (`MB_CUR_MAX` 1), so the path where a multibyte character does not fit the remaining space is not reached
-- [The narrow printf family](../../core/libs/prx/libc/src/Formatting.cpp) (libc) converts 16-bit guest wide arguments to UTF-8 on both platforms, independently of the host locale. It does not use the guest's single-byte `wcrtomb`; the console's treatment of invalid UTF-16 and locale-specific encoding remains unverified. Linux retains host formatting for formats without wide arguments, so a narrow `%p` there still follows the host (glibc prints a null pointer as `(nil)`, where FreeBSD prints `0x0`); positional arguments, the `'` flag and `%m` throw when a format requires the guest formatter
+- [The narrow printf family](../../core/libs/prx/libc/src/Formatting.cpp) (libc) converts 16-bit guest wide arguments to UTF-8 on both platforms, independently of the host locale. It does not use the guest's single-byte `wcrtomb`; the console's treatment of invalid UTF-16 and locale-specific encoding remains unverified. Linux retains host formatting for formats without wide arguments, so a narrow `%p` there still follows the host (glibc prints a null pointer as `(nil)`, where FreeBSD prints `0x0`); positional arguments and `%m` throw when a format requires the guest formatter
 - [collate<char>::_Getcat](../../core/libs/prx/libc/src/LocaleSupport.cpp) (libc) builds the facet for the C locale only and throws for any other locale name. The console's `libc.prx` stores pointers to its collation state tables at offsets 0x10 and 0x18 of the facet; ours leaves them null, as only the facet's own functions read them. `do_transform` throws for input with embedded null characters, which the console drops depending on the output buffer size, and for results of 4095 characters or more, whose string storage uses the guest's over-aligned large allocation.
 - [The scanf family](../../core/libs/prx/libc/src/Formatting.cpp) (libc) hands `%i` to glibc on Linux, which since 2.38 reads the C23 `0b`/`0B` binary prefix when the library is built as GNU C++: `sscanf("0b101", "%i", &value)` stores 5 where C17 stores 0 and stops at the `b`. The strtol family stops at the prefix as C17 does
 - [The scanf family](../../core/libs/prx/libc/include/WindowsScanning.hpp) (libc) on Windows returns 0, as C17 and FreeBSD do, when input fails after only suppressed conversions have completed (`sscanf("12", "%*d%d", &value)`). Linux hands the format to glibc, which returns `EOF` there. On Windows the host stops a `%x`, `%X`, `%i` or `%p` after the `x` of a `0x` that no hex digit follows (or that the width cuts off), and a float conversion (`%e`, `%f`, `%g`, `%a`) after the `e` of an exponent with no digits (`1e`), where C17 and FreeBSD stop before the `x` or the `e`