Make asm statement to cost at least 1 insn

[Jan Hubicka]

Hi,
this patch avoids degeneration of inliner for function containing empty
volatile asm statement.

Bootstrapped/regtested x86_64-linux, comitted.
        PR ipa/60243
        * tree-inline.c (estimate_num_insns): Set to 1 at least.
Index: ../../gcc/tree-inline.c
===================================================================
--- ../../gcc/tree-inline.c     (revision 254929)
+++ ../../gcc/tree-inline.c     (working copy)
@@ -4100,7 +4100,7 @@ estimate_num_insns (gimple *stmt, eni_we
           with very long asm statements.  */
        if (count > 1000)
          count = 1000;
-       return count;
+       return MAX (1, count);
       }
 
     case GIMPLE_RESX: