pythongh-96398: Detect emcc and mpicc in compiler names in configure

Author: erlend-aasland

configure

@@ -992,7 +992,9 @@ dnl check for GCC last, other compilers set __GNUC__, too.
 dnl msvc is listed for completeness.
 AC_CACHE_CHECK([for CC compiler name], [ac_cv_cc_name], [
 cat > conftest.c <<EOF
-#if defined(__INTEL_COMPILER) || defined(__ICC)
+#if defined(__EMSCRIPTEN__)
+  emcc
+#elif defined(__INTEL_COMPILER) || defined(__ICC)
   icc
 #elif defined(__ibmxl__) || defined(__xlc__) || defined(__xlC__)
   xlc
@@ -1009,6 +1011,9 @@ EOF
 
 if $CPP $CPPFLAGS conftest.c >conftest.out 2>/dev/null; then
   ac_cv_cc_name=`grep -v '^#' conftest.out | grep -v '^ *$' | tr -d ' 	'`
+  if $(expr "//$CC" : '.*/\(.*\)') = "mpicc"; then
+    ac_cv_cc_name="mpicc"
+  fi
 else
   ac_cv_cc_name="unknown"
 fi
@@ -1939,7 +1944,7 @@ if test "$Py_LTO" = 'true' ; then
           ;;
       esac
       ;;
-    *emcc*)
+    emcc)
       if test "$Py_LTO_POLICY" != "default"; then
         AC_MSG_ERROR([emcc supports only default lto.])
       fi