Always allocate linear memory using mmap (#3052)

With this approach we can omit using memset() for the newly allocated memory
therefore the physical pages are not being used unless touched by the program.

This also simplifies the implementation.

core/iwasm/common/wasm_runtime_common.h

@@ -320,11 +320,6 @@ LOAD_I16(void *addr)
 #define SHARED_MEMORY_UNLOCK(memory) (void)0
 #endif
 
-#if defined(OS_ENABLE_HW_BOUND_CHECK) \
-    || (WASM_ENABLE_SHARED_MEMORY != 0 && WASM_ENABLE_SHARED_MEMORY_MMAP != 0)
-#define WASM_LINEAR_MEMORY_MMAP
-#endif
-
 typedef struct WASMModuleCommon {
     /* Module type, for module loaded from WASM bytecode binary,
        this field is Wasm_Module_Bytecode, and this structure should
@@ -421,16 +416,6 @@ typedef struct WASMRegisteredModule {
 } WASMRegisteredModule;
 #endif
 
-typedef struct WASMMemoryInstanceCommon {
-    uint32 module_type;
-
-    /* The following uint8[1] member is a dummy just to indicate
-       some module_type dependent members follow.
-       Typically it should be accessed by casting to the corresponding
-       actual module_type dependent structure, not via this member. */
-    uint8 memory_inst_data[1];
-} WASMMemoryInstanceCommon;
-
 typedef package_type_t PackageType;
 typedef wasm_section_t WASMSection, AOTSection;
 
@@ -1098,14 +1083,6 @@ wasm_runtime_quick_invoke_c_api_native(WASMModuleInstanceCommon *module_inst,
 void
 wasm_runtime_show_app_heap_corrupted_prompt();
 
-void
-wasm_munmap_linear_memory(void *mapped_mem, uint64 commit_size,
-                          uint64 map_size);
-
-void *
-wasm_mmap_linear_memory(uint64_t map_size, uint64 *io_memory_data_size,
-                        char *error_buf, uint32 error_buf_size);
-
 #if WASM_ENABLE_LOAD_CUSTOM_SECTION != 0
 void
 wasm_runtime_destroy_custom_sections(WASMCustomSection *section_list);