Fix tests from previous commit

* Update some expected error messages and remove some files with
  duplicate error messages that are no longer needed.
* Remove undefined behavior in `stat.c` where padding bytes were being
  compared.

tests/general/abort.c.stderr.expected

@@ -1,6 +1,7 @@
 Error: failed to run main module `abort.c.---.wasm`
 
 Caused by:
-    0: failed to invoke command default
+    0: failed to invoke ---
     1: error while executing at wasm backtrace:
+       note: using the `WASMTIME_BACKTRACE_DETAILS=1` environment variable may show more debugging information
     2: wasm trap: wasm `unreachable` instruction executed

tests/general/abort.c.stderr.expected.filter

@@ -3,4 +3,5 @@ set -euo pipefail
 
 cat \
     | sed -e 's/main module `abort\.c\.[^`]*\.wasm`/main module `abort.c.---.wasm`/' \
+    | sed -e 's/failed to invoke.*/failed to invoke ---/' \
     | sed -E '/0x[[:xdigit:]]+/d'

tests/general/abort.c.wasm32-wasi-preview2.stderr.expected

@@ -1,6 +0,0 @@
-Error: failed to run main module `abort.c.---.wasm`
-
-Caused by:
-    0: failed to invoke `run` function
-    1: error while executing at wasm backtrace:
-    2: wasm trap: wasm `unreachable` instruction executed

tests/general/abort.c.wasm32-wasi.stderr.expected

@@ -1,6 +0,0 @@
-Error: failed to run main module `abort.c.---.wasm`
-
-Caused by:
-    0: failed to invoke command default
-    1: error while executing at wasm backtrace:
-    2: wasm trap: wasm `unreachable` instruction executed

tests/general/abort.c.wasm32-wasip2.stderr.expected

@@ -1,6 +0,0 @@
-Error: failed to run main module `abort.c.---.wasm`
-
-Caused by:
-    0: failed to invoke `run` function
-    1: error while executing at wasm backtrace:
-    2: wasm trap: wasm `unreachable` instruction executed

tests/general/assert-fail.c.stderr.expected

@@ -2,6 +2,7 @@ Assertion failed: false (assert-fail.c: main: 5)
 Error: failed to run main module `assert-fail.c.---.wasm`
 
 Caused by:
-    0: failed to invoke command default
+    0: failed to invoke ---
     1: error while executing at wasm backtrace:
+       note: using the `WASMTIME_BACKTRACE_DETAILS=1` environment variable may show more debugging information
     2: wasm trap: wasm `unreachable` instruction executed

tests/general/assert-fail.c.stderr.expected.filter

@@ -3,4 +3,5 @@ set -euo pipefail
 
 cat \
     | sed -e 's/main module `assert-fail\.c\.[^`]*\.wasm`/main module `assert-fail.c.---.wasm`/' \
+    | sed -e 's/failed to invoke.*/failed to invoke ---/' \
     | sed -E '/0x[[:xdigit:]]+/d'

tests/general/assert-fail.c.wasm32-wasi-preview2.stderr.expected

@@ -1,7 +0,0 @@
-Assertion failed: false (assert-fail.c: main: 5)
-Error: failed to run main module `assert-fail.c.---.wasm`
-
-Caused by:
-    0: failed to invoke `run` function
-    1: error while executing at wasm backtrace:
-    2: wasm trap: wasm `unreachable` instruction executed

tests/general/assert-fail.c.wasm32-wasip2.stderr.expected

@@ -1,7 +0,0 @@
-Assertion failed: false (assert-fail.c: main: 5)
-Error: failed to run main module `assert-fail.c.---.wasm`
-
-Caused by:
-    0: failed to invoke `run` function
-    1: error while executing at wasm backtrace:
-    2: wasm trap: wasm `unreachable` instruction executed

tests/general/stat.c

@@ -43,10 +43,20 @@ int main(int argc, char *argv[]) {
 
     assert(file_statbuf.st_dev == link_statbuf.st_dev);
 
-    // Clear out the access time fields, and they should be the same.
-    memset(&file_statbuf.st_atim, 0, sizeof(struct timespec));
-    memset(&link_statbuf.st_atim, 0, sizeof(struct timespec));
-    assert(memcmp(&file_statbuf, &link_statbuf, sizeof(struct stat)) == 0);
+    assert(file_statbuf.st_dev == link_statbuf.st_dev);
+    assert(file_statbuf.st_ino == link_statbuf.st_ino);
+    assert(file_statbuf.st_mode == link_statbuf.st_mode);
+    assert(file_statbuf.st_uid == link_statbuf.st_uid);
+    assert(file_statbuf.st_gid == link_statbuf.st_gid);
+    assert(file_statbuf.st_rdev == link_statbuf.st_rdev);
+    assert(file_statbuf.st_size == link_statbuf.st_size);
+    assert(file_statbuf.st_blksize == link_statbuf.st_blksize);
+    assert(file_statbuf.st_blocks == link_statbuf.st_blocks);
+    // NB: `atim` is explicitly not compared here
+    assert(file_statbuf.st_mtim.tv_sec == link_statbuf.st_mtim.tv_sec);
+    assert(file_statbuf.st_mtim.tv_nsec == link_statbuf.st_mtim.tv_nsec);
+    assert(file_statbuf.st_ctim.tv_sec == link_statbuf.st_ctim.tv_sec);
+    assert(file_statbuf.st_ctim.tv_nsec == link_statbuf.st_ctim.tv_nsec);
 
     // Test lstat.