Ports: Remove obsolete patches for Python

This enables shared library support for Python and removes
a few patches which are not necessary anymore now that
we have dlfcn support.

Ports/python3/patches/ReadMe.md

@@ -16,16 +16,6 @@ Disables check for `RLIMIT_CORE` and subsequent `setrlimit()` call. Would be ena
 
 As usual, make the `configure` script recognize Serenity.
 
-## `fix-hidden-symbol-referenced-by-dso.patch`
-
-Fix a weird build issue of `python` and other provided binaries by marking the `main()` functions `Py_EXPORTED_SYMBOL`.
-
-```text
-hidden symbol `main' in Programs/python.o is referenced by DSO
-```
-
-Not sure what the proper fix for this is, but it works fine.
-
 ## `remove-setlocale-from-preconfig.patch`
 
 Our stub implementation of `setlocale()` always returns `nullptr`, which the interpreter considers critical enough to exit right away.
@@ -33,7 +23,3 @@ Our stub implementation of `setlocale()` always returns `nullptr`, which the int
 ## `tweak-unsupported-printf-format-specifiers.patch`
 
 Replace uses of `%.Ns` with `%s` as the former is not supported by our `printf` implementation yet and would result in empty strings. It uses `snprintf` already, so this is safe.
-
-## `use-rtld-lazy-for-dlopenflags.patch`
-
-We have `RTLD_NOW` defined but don't actually support it, so use the provided `RTLD_LAZY` fallback. Doesn't help the dynamic library module import assertion though.

Ports/python3/patches/fix-autoconf.patch

@@ -16,7 +16,7 @@
         # in the case statement below.
  	case "$host" in
 +	*-*-serenity*)
-+		ac_sys_system=Serenity
++		ac_sys_system=SerenityOS
 +		;;
  	*-*-linux-android*)
  		ac_sys_system=Linux-android
@@ -38,7 +38,7 @@
         # in the case statement below.
  	case "$host" in
 +	*-*-serenity*)
-+		ac_sys_system=Serenity
++		ac_sys_system=SerenityOS
 +		;;
  	*-*-linux-android*)
  		ac_sys_system=Linux-android
@@ -53,3 +53,14 @@
  	*-*-linux*)
  		case "$host_cpu" in
  		arm*)
+diff -Naur Python-3.9.4/configure Python-3.9.4.serenity/configure
+--- Python-3.9.4/configure	2021-04-24 14:50:59.083484421 +0200
++++ Python-3.9.4.serenity/configure	2021-04-24 15:50:26.821359967 +0200
+@@ -9647,6 +9647,7 @@
+ #	    LINKFORSHARED="-Wl,-E -Wl,+s -Wl,+b\$(BINLIBDEST)/lib-dynload";;
+ 	Linux-android*) LINKFORSHARED="-pie -Xlinker -export-dynamic";;
+ 	Linux*|GNU*) LINKFORSHARED="-Xlinker -export-dynamic";;
++	SerenityOS*) LINKFORSHARED="-Xlinker -export-dynamic";;
+ 	# -u libsys_s pulls in all symbols in libsys
+ 	Darwin/*)
+ 		LINKFORSHARED="$extra_undefs -framework CoreFoundation"

Ports/python3/patches/fix-hidden-symbol-referenced-by-dso.patch

@@ -1,22 +0,0 @@
---- Python-3.9.4/Programs/python.c	2021-02-21 20:22:43.960024172 +0100
-+++ Python-3.9.4/Programs/python.c	2021-02-21 20:35:13.268988119 +0100
-@@ -9,7 +9,7 @@
-     return Py_Main(argc, argv);
- }
- #else
--int
-+Py_EXPORTED_SYMBOL int
- main(int argc, char **argv)
- {
-     return Py_BytesMain(argc, argv);
---- Python-3.9.4/Programs/_testembed.c	2021-02-21 20:22:43.959024178 +0100
-+++ Python-3.9.4/Programs/_testembed.c	2021-02-21 20:35:13.270988109 +0100
-@@ -1711,7 +1711,7 @@
-     {NULL, NULL}
- };
- 
--int main(int argc, char *argv[])
-+Py_EXPORTED_SYMBOL int main(int argc, char *argv[])
- {
-     if (argc > 1) {
-         for (struct TestCase *tc = TestCases; tc && tc->name; tc++) {

Ports/python3/patches/tweak-unsupported-printf-format-specifiers.patch

@@ -20,3 +20,21 @@
                    DATE, TIME);
      return buildinfo;
  }
+diff -Naur Python-3.9.4/Python/dynload_shlib.c Python-3.9.4.serenity/Python/dynload_shlib.c
+--- Python-3.9.4/Python/dynload_shlib.c	2021-04-04 14:56:53.000000000 +0200
++++ Python-3.9.4.serenity/Python/dynload_shlib.c	2021-04-24 15:57:27.419824682 +0200
+@@ -69,12 +69,12 @@
+ 
+     if (strchr(pathname, '/') == NULL) {
+         /* Prefix bare filename with "./" */
+-        PyOS_snprintf(pathbuf, sizeof(pathbuf), "./%-.255s", pathname);
++        PyOS_snprintf(pathbuf, sizeof(pathbuf), "./%s", pathname);
+         pathname = pathbuf;
+     }
+ 
+     PyOS_snprintf(funcname, sizeof(funcname),
+-                  LEAD_UNDERSCORE "%.20s_%.200s", prefix, shortname);
++                  LEAD_UNDERSCORE "%s_%s", prefix, shortname);
+ 
+     if (fp != NULL) {
+         int i;

Ports/python3/patches/use-rtld-lazy-for-dlopenflags.patch

@@ -1,11 +0,0 @@
---- Python-3.9.4/Python/pystate.c	2021-02-21 20:22:44.083023482 +0100
-+++ Python-3.9.4/Python/pystate.c	2021-02-21 20:30:13.907513469 +0100
-@@ -223,7 +223,7 @@
- 
-     interp->eval_frame = _PyEval_EvalFrameDefault;
- #ifdef HAVE_DLOPEN
--#if HAVE_DECL_RTLD_NOW
-+#if defined(HAVE_DECL_RTLD_NOW) && !defined(__serenity__)
-     interp->dlopenflags = RTLD_NOW;
- #else
-     interp->dlopenflags = RTLD_LAZY;