[clang] [clang] Correct FixIt ranges for unused capture warnings (PR #141148)

[Oliver Hunt via cfe-commits]

================
@@ -0,0 +1,250 @@
+// RUN: cp %s %t
+// RUN: %clang_cc1 -x c++ -Wunused-lambda-capture -Wno-unused-value -std=c++1z -fixit %t
+// RUN: grep -v CHECK %t | FileCheck %s
+
+
+#define MACRO_CAPTURE(...) __VA_ARGS__
+int main() {
+    int a = 0, b = 0, c = 0;
+    auto F0 = [a, &b]() mutable {
+    // CHECK: auto F0 = [a]()
+        a++;
+    };
+
+    auto F1 = [&a, &b]() {
+    // CHECK: auto F1 = []() {
+    };
+
+    auto F2 = [&a, b]() {
+    // CHECK: auto F2 = []() {
+    };
+
+    auto F3 = [&a,
+         &b]() {
+    // CHECK: auto F3 = []() {
+    };
+
+    auto F4 = [&a
+        , &b]() {
+    // CHECK: auto F4 = []() {
+    };
+    auto F5 = [&a ,&b]()  {
+    // CHECK: auto F5 = []() {
+    };
+
+    auto F0a = [a, &b]() mutable {
+    // CHECK: auto F0a = [a]() mutable {
+        a++;
+    };
+
+    auto F1a = [&a, &b]() {
+    // CHECK: auto F1a = [&a]() {
+        a++;
+    };
+
+    auto F2a = [&a, b]() {
+    // CHECK: auto F2a = [&a]() {
+        a++;
+    };
+
+    auto F3a = [&a,
+         &b]() {
+    // CHECK: auto F3a = [&a]() {
+        a++;
+    };
+
+    auto F4a = [&a
+        , &b]() {
+    // CHECK: auto F4a = [&a]() {
+        a++;
+    };
+
+    auto F5a = [&a ,&b]() {
+    // CHECK: auto F5a = [&a]() {
+        a++;
+    };
+    auto F0b = [a, &b]() mutable {
+    // CHECK: auto F0b = [ &b]() mutable
+        b++;
+    };
+
+    auto F1b = [&a, &b]() {
+    // CHECK: auto F1b = [ &b]() {
+        b++;
+    };
+
+    auto F2b = [&a, b]() mutable {
+    // CHECK: auto F2b = [ b]() mutable {
+        b++;
+    };
+
+    auto F3b = [&a,
+         &b]() {
+    // CHECK: auto F3b = [ &b]() {
+        b++;
+    };
+
+    auto F4b = [&a
+        , &b]() {
+    // CHECK: auto F4b = [ &b]() {
+        b++;
+    };
+    auto F5b = [&a ,&b]() {
+    // CHECK: auto F5b = [&b]() {
+        b++;
+    };
+
+    auto F6 = [&a, &b, &c]() {
+    // CHECK: auto F6 = [&a, &b]() {
+        a++;
+        b++;
+    };
+    auto F7 = [&a, &b, &c]() {
+    // CHECK: auto F7 = [&a, &c]() {
+        a++;
+        c++;
+    };
+    auto F8 = [&a, &b, &c]() {
+    // CHECK: auto F8 = [ &b, &c]() {
+        b++;
+        c++;
+    };
+    auto F9 = [&a, &b    , &c]() {
----------------
ojhunt wrote:

yeah, I'm currently on vacation so trying very hard not to work despite that being my default :D

but having multiple unused in the middle is a good idea - I'm not sure how/if fixits merge neighboring equivalent fixits - but something like

```
...[used, unused, used, unused, used]...
```
and
```
...[used, unused, unused, used]
```
seems like a good call

- [ ] (trying to add a task to do this in case the terrible GH UI actually surfaces tasks)

https://github.com/llvm/llvm-project/pull/141148