feat: add process termination codes and SYS_ABORT; whole-process abort() from any thread in libc and montauk-rt

programs/src/shell/exec.cpp

@@ -23,9 +23,9 @@ static void print_exit_code(const int exitCode) {
     if (code == 0) return;
     char buf[16];
     int n = 0;
-    if (code >= 256) {
+    if (code >= montauk::TerminationBase) {
         montauk::print("[terminated by signal ");
-        code -= 256;
+        code -= montauk::TerminationBase;
     } else {
         montauk::print("[exit code ");
     }
@@ -39,13 +39,16 @@ static void print_exit_code(const int exitCode) {
         montauk::print(c);
     }
     
-    if (exitCode > 0 && exitCode <= montauk::MaxStatusCode) {
-        const char* statusText = montauk::GetStatusText((montauk::StatusCode)exitCode);
-        
-        if (statusText != nullptr) {
-            montauk::print(" - ");
-            montauk::print(statusText);
-        }
+    const char* statusText = nullptr;
+    if (exitCode >= montauk::TerminationBase) {
+        statusText = montauk::GetTerminationText(exitCode);
+    } else if (exitCode > 0 && exitCode <= montauk::MaxStatusCode) {
+        statusText = montauk::GetStatusText((montauk::StatusCode)exitCode);
+    }
+
+    if (statusText != nullptr) {
+        montauk::print(" - ");
+        montauk::print(statusText);
     }
 
     montauk::print("]\n");