transpile: Add snapshot tests for array decay and address-of array

Author: Rua

c2rust-transpile/tests/snapshots/arrays.c

@@ -25,7 +25,14 @@ void entry(void) {
     char char_too_long[3] = "abcde";
     char char_too_short[20] = "abc";
 
-    char *char_ptr = "abc";
+    int *int_var_ptr = int_empty_init;
+    int (*int_var_array_ptr)[16] = &int_empty_init;
+    char *char_var_ptr_var = char_with_string;
+    char (*char_var_array_ptr)[4] = &char_with_string;
+    const char *const_char_lit_ptr = "abc";
+    const char (*const_char_lit_array_ptr)[4] = &"abc";
+    char *char_lit_ptr = "abc";
+    char (*char_lit_array_ptr)[4] = &"abc";
 
 // TODO re-enable after #1266 adds portable support for translating `wchar_t`.
 #if 0

c2rust-transpile/tests/snapshots/[email protected]

@@ -79,8 +79,20 @@ pub unsafe extern "C" fn entry() {
         ::core::mem::transmute::<[u8; 20], [::core::ffi::c_char; 20]>(
             *b"abc\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0",
         );
-    let mut char_ptr: *mut ::core::ffi::c_char =
+    let mut int_var_ptr: *mut ::core::ffi::c_int = int_empty_init.as_mut_ptr();
+    let mut int_var_array_ptr: *mut [::core::ffi::c_int; 16] = &mut int_empty_init;
+    let mut char_var_ptr_var: *mut ::core::ffi::c_char = char_with_string.as_mut_ptr();
+    let mut char_var_array_ptr: *mut [::core::ffi::c_char; 4] = &mut char_with_string;
+    let mut const_char_lit_ptr: *const ::core::ffi::c_char =
+        b"abc\0" as *const u8 as *const ::core::ffi::c_char;
+    let mut const_char_lit_array_ptr: *const [::core::ffi::c_char; 4] =
+        &::core::mem::transmute::<[u8; 4], [::core::ffi::c_char; 4]>(*b"abc\0")
+            as *const [::core::ffi::c_char; 4];
+    let mut char_lit_ptr: *mut ::core::ffi::c_char =
         b"abc\0" as *const u8 as *const ::core::ffi::c_char as *mut ::core::ffi::c_char;
+    let mut char_lit_array_ptr: *mut [::core::ffi::c_char; 4] =
+        &::core::mem::transmute::<[u8; 4], [::core::ffi::c_char; 4]>(*b"abc\0")
+            as *const [::core::ffi::c_char; 4] as *mut [::core::ffi::c_char; 4];
     let mut past_end: *mut ::core::ffi::c_char = &mut *simple
         .as_mut_ptr()
         .offset(::core::mem::size_of::<[::core::ffi::c_char; 9]>() as isize)