options/rtdl: Fix alignment overhead computation for the TLS allocation

The alignment overhead is used to properly align the TCB, which on x86_64
needs to be aligned to the max TLS block alignment so that accessing
blocks before it yields aligned addresses.

Fixes #960.

options/rtdl/generic/linker.cpp

@@ -885,7 +885,7 @@ Tcb *allocateTcb() {
 
 	// To make sure that both the TCB and TLS data are sufficiently aligned, allocate
 	// slightly more than necessary and adjust alignment afterwards.
-	size_t alignOverhead = frg::min(alignof(Tcb), tlsMaxAlignment);
+	size_t alignOverhead = frg::max(alignof(Tcb), tlsMaxAlignment);
 	size_t allocSize = tlsInitialSize + sizeof(Tcb) + alignOverhead;
 	auto allocation = reinterpret_cast<uintptr_t>(getAllocator().allocate(allocSize));
 	memset(reinterpret_cast<void *>(allocation), 0, allocSize);