Compat work towards making bash-5.0 build with less patches.

Hacked implementations of sigsetjmp() and siglongjmp(). I didn't know about
these APIs until just now, but I hope I got them right.

Kernel/Process.cpp

@@ -1968,7 +1968,9 @@ int Process::sys$select(const Syscall::SC_select_params* params)
     auto* timeout = params->timeout;
 
     // FIXME: Implement exceptfds support.
-    ASSERT(!exceptfds);
+    //ASSERT(!exceptfds);
+    if (exceptfds)
+        kprintf("%s(%u): FIXME: select() with exceptfds\n", name().characters(), pid());
 
     if (timeout) {
         m_select_timeout = *timeout;

LibC/locale.h

@@ -13,7 +13,9 @@ enum {
 };
 
 struct lconv {
-    char *decimal_point;
+    char* decimal_point;
+    char* thousands_sep;
+    char* grouping;
 };
 
 struct lconv* localeconv();

LibC/setjmp.h

@@ -2,12 +2,24 @@
 
 #include <sys/cdefs.h>
 #include <sys/types.h>
+#include <stdint.h>
+#include <signal.h>
+#include <stdbool.h>
 
 __BEGIN_DECLS
 
-typedef uint32_t jmp_buf[6];
+struct __jmp_buf {
+    uint32_t regs[6];
+    bool did_save_signal_mask;
+    sigset_t saved_signal_mask;
+};
+
+typedef struct __jmp_buf jmp_buf[1];
 
 int setjmp(jmp_buf);
 void longjmp(jmp_buf, int val);
 
+int sigsetjmp(jmp_buf, int savesigs);
+void siglongjmp(jmp_buf, int val);
+
 __END_DECLS

LibC/signal.cpp

@@ -2,6 +2,8 @@
 #include <errno.h>
 #include <signal.h>
 #include <stdio.h>
+#include <setjmp.h>
+#include <assert.h>
 #include <Kernel/Syscall.h>
 
 extern "C" {
@@ -106,4 +108,24 @@ const char* sys_siglist[NSIG] = {
 #undef __SIGNAL
 };
 
+int sigsetjmp(jmp_buf env, int savesigs)
+{
+    if (savesigs) {
+        int rc = sigprocmask(0, nullptr, &env->saved_signal_mask);
+        assert(rc == 0);
+        env->did_save_signal_mask = true;
+    } else {
+        env->did_save_signal_mask = false;
+    }
+    return setjmp(env);
+}
+void siglongjmp(jmp_buf env, int val)
+{
+    if (env->did_save_signal_mask) {
+        int rc = sigprocmask(SIG_SETMASK, &env->saved_signal_mask, nullptr);
+        assert(rc == 0);
+    }
+    longjmp(env, val);
+}
+
 }

LibC/stdbool.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#ifndef __cplusplus
+
 #include <sys/cdefs.h>
 
 __BEGIN_DECLS
@@ -11,3 +13,4 @@ __BEGIN_DECLS
 
 __END_DECLS
 
+#endif

LibC/stdlib.h

@@ -2,6 +2,7 @@
 
 #include <sys/cdefs.h>
 #include <sys/types.h>
+#include <stddef.h>
 
 __BEGIN_DECLS
 

LibC/unistd.h

@@ -35,6 +35,7 @@ gid_t getegid();
 uid_t getuid();
 gid_t getgid();
 pid_t getpid();
+pid_t getppid();
 int getgroups(int size, gid_t list[]);
 int setgroups(size_t, const gid_t*);
 int setuid(uid_t);