[build] Use platform.sh file after checking submodules

As this script is part of laf submodule, we have to check the existence
of submodules first, and then run the script.

We've also moved the cl.exe check to build.sh directly.

build.sh

@@ -56,11 +56,6 @@ if [ "$1" == "--norun" ] ; then
     norun=1
 fi
 
-# Platform.
-if ! source "$pwd/laf/misc/platform.sh" ; then
-    exit $?
-fi
-
 # Check utilities.
 if ! cmake --version >/dev/null ; then
     echo ""
@@ -117,6 +112,23 @@ if [ $run_submodule_update ] ; then
     echo "Done"
 fi
 
+# Platform.
+if ! source "$pwd/laf/misc/platform.sh" ; then
+    exit $?
+fi
+
+if [ $is_win ] ; then
+    # Check MSVC compiler.
+    if ! cl.exe >/dev/null 2>/dev/null ; then
+        echo ""
+        echo "MSVC compiler (cl.exe) not found in PATH"
+        echo ""
+        echo "  PATH=$PATH"
+        echo ""
+        exit 1
+    fi
+fi
+
 # Create the directory to store the configuration.
 if [ ! -d "$pwd/.build" ] ; then
     mkdir "$pwd/.build"
@@ -130,7 +142,7 @@ if [ ! -f "$pwd/.build/userkind" ] ; then
         echo "user" > $pwd/.build/userkind
     else
         echo ""
-        echo "Select what kind of user you are (press U or D keys):"
+        echo "Select what kind of user you are (press U or D key and then Enter):"
         echo ""
         echo "  [U]ser: give a try to Aseprite"
         echo "  [D]eveloper: develop/modify Aseprite"

laf

@@ -1 +1 @@
-Subproject commit ef0c63aa77871d8ff77aa0c66d025656c76bbbfa
+Subproject commit 914ab82a6ed356570ed4a4ca1ee6bc0fb9a1295d