user: implement mlibc as the libc, finally.

It's finally done..

Signed-off-by: kaguya <vpshinomiya@protonmail.com>

user/include/mlibc/options/lsb/generic/tls.cpp

@@ -0,0 +1,23 @@
+#include <internal-config.h>
+#include <mlibc/thread.hpp>
+#include <mlibc/rtld-abi.hpp>
+
+#if (defined(__riscv) || defined(__m68k__) || defined(__loongarch64)) && defined(MLIBC_STATIC_BUILD)
+	// On RISC-V, m68k and loongarch64, linker optimisation is not guaranteed and so we may
+	// still get calls to this function in statically linked binaries.
+	// TODO: This will break dlopen calls from statically linked programs.
+	extern "C" void *__tls_get_addr(struct __abi_tls_entry *entry) {
+		Tcb *tcbPtr = mlibc::get_current_tcb();
+		auto dtvPtr = reinterpret_cast<char *>(tcbPtr->dtvPointers[0]);
+		return reinterpret_cast<void *>(dtvPtr + entry->offset + TLS_DTV_OFFSET);
+	}
+#elif defined(__i386__)
+	extern "C" __attribute__((regparm(1))) void *___tls_get_addr(struct __abi_tls_entry *entry) {
+		return __dlapi_get_tls(entry);
+	}
+#else
+	extern "C" void *__tls_get_addr(struct __abi_tls_entry *entry) {
+		return __dlapi_get_tls(entry);
+	}
+#endif
+