[3.11] gh-90473: Define HOSTRUNNER for WASI (GH-93606) (GH-93612)

(cherry picked from commit 22df2e0322300d25c1255ceb73cacc0ebd96b20e)

Co-authored-by: Christian Heimes <christian@python.org>
diff --git a/configure b/configure
index e91d04b..2ad709c 100755
--- a/configure
+++ b/configure
@@ -6688,6 +6688,8 @@
 
 fi
      ;; #(
+              WASI/*) :
+    HOSTRUNNER='wasmtime run --env PYTHONPATH=$$(realpath --relative-to $(abs_srcdir) $(abs_builddir))/$$(cat pybuilddir.txt) --mapdir /::$(srcdir) --' ;; #(
   *) :
     HOSTRUNNER=''
    ;;
diff --git a/configure.ac b/configure.ac
index 2e2e24c..c1ea163 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1424,6 +1424,10 @@
         HOSTRUNNER='node'
       ])
     ],
+    dnl TODO: support other WASI runtimes
+    dnl wasmtime starts the proces with "/" as CWD. For OOT builds add the
+    dnl directory containing _sysconfigdata to PYTHONPATH.
+    [WASI/*], [HOSTRUNNER='wasmtime run --env PYTHONPATH=$$(realpath --relative-to $(abs_srcdir) $(abs_builddir))/$$(cat pybuilddir.txt) --mapdir /::$(srcdir) --'],
     [HOSTRUNNER='']
   )
 fi