Don't initialize the static TLS area in single-threaded builds

Author: Aransentin

lib/std/start.zig

@@ -437,20 +437,22 @@ fn posixCallMainAndExit() callconv(.C) noreturn {
             std.os.linux.pie.relocate(phdrs);
         }
 
-        // ARMv6 targets (and earlier) have no support for TLS in hardware.
-        // FIXME: Elide the check for targets >= ARMv7 when the target feature API
-        // becomes less verbose (and more usable).
-        if (comptime native_arch.isARM()) {
-            if (at_hwcap & std.os.linux.HWCAP.TLS == 0) {
-                // FIXME: Make __aeabi_read_tp call the kernel helper kuser_get_tls
-                // For the time being use a simple abort instead of a @panic call to
-                // keep the binary bloat under control.
-                std.os.abort();
+        if (!builtin.single_threaded) {
+            // ARMv6 targets (and earlier) have no support for TLS in hardware.
+            // FIXME: Elide the check for targets >= ARMv7 when the target feature API
+            // becomes less verbose (and more usable).
+            if (comptime native_arch.isARM()) {
+                if (at_hwcap & std.os.linux.HWCAP.TLS == 0) {
+                    // FIXME: Make __aeabi_read_tp call the kernel helper kuser_get_tls
+                    // For the time being use a simple abort instead of a @panic call to
+                    // keep the binary bloat under control.
+                    std.os.abort();
+                }
             }
-        }
 
-        // Initialize the TLS area.
-        std.os.linux.tls.initStaticTLS(phdrs);
+            // Initialize the TLS area.
+            std.os.linux.tls.initStaticTLS(phdrs);
+        }
 
         // The way Linux executables represent stack size is via the PT_GNU_STACK
         // program header. However the kernel does not recognize it; it always gives 8 MiB.