Added virtual memory on Linux

code/os/core.c

@@ -1,3 +1,5 @@
 #if OS_WINDOWS
 	#include "impl/windows/core.c"
+#elif OS_LINUX
+	#include "impl/linux/core.c"
 #endif

code/os/impl/linux/core.c

@@ -0,0 +1,31 @@
+U64 VM_PageSize() {
+	U64 result = getpagesize();
+	return result;
+}
+
+U64 VM_AllocationGranularity() {
+	U64 result = getpagesize();
+	return result;
+}
+
+void *VM_Reserve(U64 size) {
+	void *addr = mmap(0, size, PROT_NONE, MAP_ANON | MAP_PRIVATE, -1, 0);
+
+	void *result = (addr == MAP_FAILED) ? 0 : addr;
+	return result;
+}
+
+B32 VM_Commit(void *base, U64 size) {
+	B32 result = mprotect(base, size, PROT_READ | PROT_WRITE) == 0;
+	return result;
+}
+
+void VM_Decommit(void *base, U64 size) {
+	mprotect(base, size, PROT_NONE);
+}
+
+void VM_Release(void *base, U64 size) {
+	munmap(base, size);
+}
+
+