Add a patch to prevent Julia running out of virtual memory

var/spack/packages/julia/gc.patch

@@ -0,0 +1,11 @@
+--- julia/src/gc.c
++++ julia/src/gc.c
+@@ -162,7 +162,7 @@
+ // A region is contiguous storage for up to REGION_PG_COUNT naturally aligned GC_PAGE_SZ pages
+ // It uses a very naive allocator (see malloc_page & free_page)
+ #if defined(_P64) && !defined(_COMPILER_MICROSOFT_)
+-#define REGION_PG_COUNT 16*8*4096 // 8G because virtual memory is cheap
++#define REGION_PG_COUNT 8*4096 // 512M
+ #else
+ #define REGION_PG_COUNT 8*4096 // 512M
+ #endif

var/spack/packages/julia/package.py

@@ -8,6 +8,8 @@ class Julia(Package):
 
     version('0.4.2', 'ccfeb4f4090c8b31083f5e1ccb03eb06')
 
+    patch('gc.patch')
+
     # Build-time dependencies
     depends_on("cmake @2.8:")
     # depends_on("awk")