Add compilation for 32-bit linux

Both 64-bit and 32-bit ones work on my 64-bit Linux

.gitlab-ci.yml

@@ -21,6 +21,10 @@ include:
   # Linux 64-bit
   - project: 'libretro-infrastructure/ci-templates'
     file: '/linux-x64.yml'
+
+  # Linux 32-bit
+  - project: 'libretro-infrastructure/ci-templates'
+    file: '/linux-i686.yml'
     
   ################################## CELLULAR ################################
   # Android
@@ -49,7 +53,13 @@ libretro-build-linux-x64:
   extends:
     - .libretro-linux-x64-make-default
     - .core-defs
-    
+
+# Linux 32-bit
+libretro-build-linux-i686:
+  extends:
+    - .libretro-linux-i686-make-default
+    - .core-defs
+
 ################################### CELLULAR #################################
 # Android ARMv7a
 android-armeabi-v7a: