tcg: Move tcg_init_ctx and tcg_ctx from accel/tcg/

These variables belong to the jit side, not the user side.

Since tcg_init_ctx is no longer used outside of tcg/, move
the declaration to tcg-internal.h.

Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Luis Pires <luis.pires@eldorado.org.br>
Suggested-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
diff --git a/tcg/tcg-internal.h b/tcg/tcg-internal.h
index f990652..181f865 100644
--- a/tcg/tcg-internal.h
+++ b/tcg/tcg-internal.h
@@ -27,6 +27,7 @@
 
 #define TCG_HIGHWATER 1024
 
+extern TCGContext tcg_init_ctx;
 extern TCGContext **tcg_ctxs;
 extern unsigned int tcg_cur_ctxs;
 extern unsigned int tcg_max_ctxs;