Minor tweak to support compiling with TCC

Makefile

@@ -1,7 +1,7 @@
 NAME=bb
 PREFIX=
-CC=gcc
-O=-O2
+CC ?= gcc
+O ?= -O2
 CFLAGS=-std=c99 -D_XOPEN_SOURCE=500 -D_GNU_SOURCE -D_POSIX_C_SOURCE=200809L
 CWARN=-Wall -Wpedantic -Wextra -Wno-unknown-pragmas -Wno-missing-field-initializers\
 	  -Wno-padded -Wsign-conversion -Wno-missing-noreturn -Wno-cast-qual -Wtype-limits

bb.h

@@ -245,4 +245,10 @@ static const struct termios default_termios = {
 static const char *description_str = "bb - an itty bitty console TUI file browser\n";
 static const char *usage_str = "Usage: bb (-h/--help | -v/--version | -s | -d | -0 | +command)* [[--] directory]\n";
 
+// Hack to get TinyCC (TCC) compilation to work:
+// https://lists.nongnu.org/archive/html/tinycc-devel/2018-07/msg00000.html
+#ifdef __TINYC__
+void * __dso_handle __attribute((visibility("hidden"))) = &__dso_handle;
+#endif
+
 // vim: ts=4 sw=0 et cino=L2,l1,(0,W4,m1