Patch shebangs in source that gets unpacked by `configure'.

--- bigloo3.9a/gc/install-gc-7.2d	2013-01-14 15:24:01.000000000 +0100
+++ bigloo3.9a/gc/install-gc-7.2d	2013-01-14 15:23:51.000000000 +0100
@@ -29,9 +29,11 @@ fi
 # untar the two versions of the GC
 $tar xfz $src -C ../gc || (echo "$tar xfz $src failed"; exit 1)
 /bin/rm -rf "../gc/$gc"_fth
+find ../gc/gc-7.2 -perm /111 -type f | xargs sed -i -e"s|/bin/sh|`type -P bash`|g"
 mv ../gc/gc-7.2 "../gc/$gc"_fth || (echo "mv gc-7.2 failed"; exit 1)
 
 $tar xfz $src  -C ../gc || (echo "$tar xfz $src failed"; exit 1)
+find ../gc/gc-7.2 -perm /111 -type f | xargs sed -i -e"s|/bin/sh|`type -P bash`|g"
 mv ../gc/gc-7.2 "../gc/$gc"
 
 # general Bigloo patch