[ips_layer] remove trailing whitespace to fix hex parsing on TLTD mods (#4336)

Signed-off-by: lizzie <lizzie@eden-emu.dev>

- [x] I have read and followed the [Contribution Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/CONTRIBUTING.md#code-contributions).
- [x] I have read and followed the [AI Policy](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/AI.md)
- [x] I have read and followed the [Coding Guidelines](https://git.eden-emu.dev/eden-emu/eden/src/branch/master/docs/policies/Coding.md) to the best of my ability.

-------------------

...another edge case, this time with
`00297f24 34008052 // 60FPS`
would get parsed as
`34008052 `
which isn't quite correct

Reviewed-on: https://git.eden-emu.dev/eden-emu/eden/pulls/4336
Reviewed-by: CamilleLaVey <camillelavey99@gmail.com>
Reviewed-by: Maufeat <sahyno1996@gmail.com>

src/core/file_sys/ips_layer.cpp

@@ -120,7 +120,7 @@ std::array<u8, 32> IPSwitchCompiler::GetBuildID() const {
 
 static IPSwitchRecord EscapeStringSequences(std::string_view sv) {
     IPSwitchRecord r{};
-    for (auto it = sv.cbegin(); it != sv.cend(); ) {
+    for (auto it = sv.cbegin(); it < sv.cend(); ) {
         if (*it == '\\' && it + 1 < sv.cend()) {
             switch (it[1]) {
             case 'a': r.data[r.count] = '\a'; break;
@@ -198,6 +198,8 @@ void IPSwitchCompiler::Parse(std::span<u8 const> bytes) {
                 LOG_WARNING(Loader, "Unknown flag {}", line);
                 break;
             }
+        } else if (patches.empty()) {
+            LOG_WARNING(Loader, "Invalid line not in a patch {}", line);
         } else {
             size_t offset = size_t(std::strtoul(line.data(), nullptr, 16));
             offset += size_t(offset_shift);
@@ -253,25 +255,30 @@ void IPSwitchCompiler::Parse(std::span<u8 const> bytes) {
             // now make a nominal preprocessed line: remove comments
             char quote = '\0';
             auto const sline_start = p;
+            auto last_char = p;
             for (; p < sline.cend(); ) {
                 // we dont check for "//", IPS checks for '/' only...
-                if ((!quote && p[0] == '/')
+                if (std::isspace(*p)) {
+                    ++p;
+                } else if ((!quote && p[0] == '/')
                 || (!quote && p[0] == '#')) {
                     break;
                 } else if (p[0] == '\"' || p[0] == '\'') {
                     quote = (p[0] == quote) ? '\0' : p[0];
                     ++p;
+                    last_char = p;
                 } else if (p + 1 < sline.cend() && p[0] == '\\') {
                     p += 2;
+                    last_char = p;
                 } else {
                     ++p;
+                    last_char = p;
                 }
             }
             // now we have the preprocessed string ;)
-            std::string_view pp_str(sline_start, p);
-            if (pp_str.size() > 0 && !parse_line(pp_str)) {
+            std::string_view const pp_str(sline_start, last_char);
+            if (pp_str.size() > 0 && !parse_line(pp_str))
                 break;
-            }
         }
     }
 }