Fix timespec/localtime (#981)

* fix localtime timespec

* fix localtime timespec

Author: rennergade

src/glibc/target/include/bits/types/struct_timespec.h

@@ -32,9 +32,10 @@
 
 struct timespec
 {
-  __time64_t tv_sec;		/* Seconds.  */
-  long int tv_nsec;  /* Nanoseconds.  */
+  time_t tv_sec;		/* Seconds.  */
   __int32_t __padding;           /* Padding.  */
+  long int tv_nsec;  /* Nanoseconds.  */
+  __int32_t __padding2;           /* Padding.  */
 };
 
 #endif

tests/unit-tests/file_tests/deterministic/timespec_time_t_compat.c

@@ -0,0 +1,30 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include <sys/stat.h>
+#include <assert.h>
+
+int main() {
+    /* Verify struct timespec.tv_sec is time_t (POSIX requirement).
+       This was broken when the installed header used __time64_t
+       instead of time_t for tv_sec on wasm32. */
+
+    /* 1. sizeof check: tv_sec must be the same size as time_t */
+    struct timespec ts;
+    assert(sizeof(ts.tv_sec) == sizeof(time_t));
+
+    /* 2. Type compatibility: &ts.tv_sec must be assignable to time_t* */
+    time_t *tp = &ts.tv_sec;
+    (void)tp;
+
+    /* 3. The actual use case that broke: stat + localtime */
+    struct stat st;
+    int ret = stat("/", &st);
+    assert(ret == 0);
+
+    struct tm *tm = localtime(&st.st_mtime);
+    assert(tm != NULL);
+
+    printf("timespec_time_t_compat: all checks passed\n");
+    return 0;
+}