added missing MADV_DONTDUMP calls.

Author: mangod9

src/coreclr/gc/unix/gcenv.unix.cpp

@@ -661,6 +661,11 @@ static void* VirtualReserveInner(size_t size, size_t alignment, uint32_t flags,
         pRetVal = pAlignedRetVal;
     }
 
+#ifdef MADV_DONTDUMP
+    // Do not include reserved memory in coredump.
+    madvise(pRetVal, size, MADV_DONTDUMP);
+#endif
+
     return pRetVal;
 }
 
@@ -765,7 +770,14 @@ bool GCToOSInterface::VirtualDecommit(void* address, size_t size)
     // that much more clear to the operating system that we no
     // longer need these pages. Also, GC depends on re-committed pages to
     // be zeroed-out.
-    return mmap(address, size, PROT_NONE, MAP_FIXED | MAP_ANON | MAP_PRIVATE, -1, 0) != NULL;
+    void* bRetVal = mmap(address, size, PROT_NONE, MAP_FIXED | MAP_ANON | MAP_PRIVATE, -1, 0);
+
+#ifdef MADV_DONTDUMP
+    // Do not include freed memory in coredump.
+    madvise(address, size, MADV_DONTDUMP);
+#endif
+
+    return  (bRetVal != NULL);
 }
 
 // Reset virtual memory range. Indicates that data in the memory range specified by address and size is no
@@ -796,6 +808,11 @@ bool GCToOSInterface::VirtualReset(void * address, size_t size, bool unlock)
 #endif
     }
 
+#ifdef MADV_DONTDUMP
+        // Do not include reset memory in coredump.
+        madvise(address, size, MADV_DONTDUMP);
+#endif
+
     return (st == 0);
 }