gh-111225: Link extension modules against libpython on Android (#115780)

Part of the work on PEP 738: Adding Android as a supported platform.

* Rename the LIBPYTHON variable to MODULE_LDFLAGS, to more accurately 
  reflect its purpose.
* Edit makesetup to use MODULE_LDFLAGS when linking extension modules.
* Edit the Makefile so that extension modules depend on libpython on 
  Android and Cygwin.
* Restore `-fPIC` on Android. It was removed several years ago with a 
  note that the toolchain used it automatically, but this is no longer
  the case. Omitting it causes all linker commands to fail with an error
  like `relocation R_AARCH64_ADR_PREL_PG_HI21 cannot be used against
  symbol '_Py_FalseStruct'; recompile with -fPIC`.

1 files changed, 1 insertions, 13 deletions

diff --git a/Modules/makesetup b/Modules/makesetup
index f000c9c..d41b664 100755
--- a/Modules/makesetup
+++ b/Modules/makesetup
@@ -87,18 +87,6 @@ esac
 NL='\
 '
 
-# Setup to link with extra libraries when making shared extensions.
-# Currently, only Cygwin needs this baggage.
-case `uname -s` in
-CYGWIN*) if test $libdir = .
-	 then
-	 	ExtraLibDir=.
-	 else
-	 	ExtraLibDir='$(LIBPL)'
-	 fi
-	 ExtraLibs="-L$ExtraLibDir -lpython\$(LDVERSION)";;
-esac
-
 # Main loop
 for i in ${*-Setup}
 do
@@ -286,7 +274,7 @@ sed -e 's/[ 	]*#.*//' -e '/^[ 	]*$/d' |
 				;;
 			esac
 			rule="$file: $objs"
-			rule="$rule; \$(BLDSHARED) $objs $libs $ExtraLibs -o $file"
+			rule="$rule; \$(BLDSHARED) $objs $libs \$(MODULE_LDFLAGS) -o $file"
 			echo "$rule" >>$rulesf
 		done
 	done