cmd/gc: must not inline panic, recover

R=lvd, gri
CC=golang-dev
https://golang.org/cl/5731061

src/cmd/gc/inl.c

@@ -182,6 +182,8 @@ ishairy(Node *n, int *budget)
 	case OCALLFUNC:
 	case OCALLINTER:
 	case OCALLMETH:
+	case OPANIC:
+	case ORECOVER:
 		if(debug['l'] < 4)
 			return 1;
 		break;

test/escape4.go

@@ -31,3 +31,9 @@ func f1() {
 	}
 	f()
 }
+
+func f2() {} // ERROR "can inline f2"
+
+// No inline for panic, recover.
+func f3() { panic(1) }
+func f4() { recover() }