add tests

scripts/regression_tests.pd

-#N canvas 340 157 750 572 12;
+#N canvas 225 102 750 572 12;
 #X obj 465 281 r \$0-result;
 #X obj 212 239 bng 31 250 50 0 empty empty Run_all 39 13 0 12 -262144
 -1 -1;
@@ -59,6 +59,7 @@ is handy for some binbuf tests.;
 #X obj 198 2031 rtest type_hint_coverage;
 #X obj 198 2086 rtest route_reject_bang;
 #X obj 198 2141 rtest text_sort;
+#X obj 198 2196 rtest pow~_negative_numbers;
 #X connect 0 0 27 0;
 #X connect 1 0 4 0;
 #X connect 2 0 42 0;
@@ -103,3 +104,4 @@ is handy for some binbuf tests.;
 #X connect 50 0 51 0;
 #X connect 51 0 52 0;
 #X connect 52 0 53 0;
+#X connect 53 0 54 0;

scripts/regression_tests/pow~_negative_numbers.pd

+#N canvas 320 117 911 463 12;
+#X obj 41 28 inlet;
+#X obj 41 404 outlet;
+#X msg 41 56 bang;
+#X msg 41 135 -2;
+#X obj 41 164 ../utils/sigtofloat~ pow~ 2;
+#X obj 41 193 == 4;
+#X obj 41 222 list append pow~ should handle negative numbers correctly
+for integer powers;
+#X obj 41 85 trigger bang bang;
+#X msg 461 135 -2;
+#X obj 461 164 ../utils/sigtofloat~ pow~ 2.5;
+#X obj 461 222 list append pow~ should output zero for negative numbers
+when given a non-integer power;
+#X obj 461 193 == 0;
+#X connect 0 0 2 0;
+#X connect 2 0 7 0;
+#X connect 3 0 4 0;
+#X connect 4 0 5 0;
+#X connect 5 0 6 0;
+#X connect 6 0 1 0;
+#X connect 7 0 3 0;
+#X connect 7 1 8 0;
+#X connect 8 0 9 0;
+#X connect 9 0 11 0;
+#X connect 10 0 1 0;
+#X connect 11 0 10 0;

scripts/regression_tests/wrap~_compatibility_bug.pd

-#N canvas 78 98 647 470 12;
+#N canvas 79 122 647 470 12;
 #X obj 18 15 inlet;
 #X obj 508 171 ../utils/sigtofloat~ wrap~;
 #X floatatom 508 200 5 0 0 0 - - -, f 5;

scripts/utils/sigtofloat~.pd

-#N canvas 738 437 450 381 12;
+#N canvas 739 461 450 381 12;
 #X obj 26 20 inlet;
-#X obj 149 160 \$1;
 #X obj 149 134 sig~;
 #X obj 149 189 snapshot~;
 #X obj 26 76 t b b a b;
@@ -14,15 +13,16 @@
 float is converted to leftmost signal inlet. A single block is computed
 to generate the float output.;
 #X obj 149 218 outlet;
-#X connect 0 0 4 0;
-#X connect 1 0 3 0;
-#X connect 2 0 1 0;
-#X connect 3 0 12 0;
-#X connect 4 0 8 0;
-#X connect 4 1 7 0;
-#X connect 4 2 2 0;
-#X connect 4 3 5 0;
-#X connect 5 0 6 0;
+#X obj 149 160 \$@;
+#X connect 0 0 3 0;
+#X connect 1 0 12 0;
+#X connect 2 0 11 0;
+#X connect 3 0 7 0;
+#X connect 3 1 6 0;
+#X connect 3 2 1 0;
+#X connect 3 3 4 0;
+#X connect 4 0 5 0;
+#X connect 7 0 8 0;
+#X connect 7 1 2 0;
 #X connect 8 0 9 0;
-#X connect 8 1 3 0;
-#X connect 9 0 10 0;
+#X connect 12 0 2 0;