Inline a method that mainly serves to confuse the compiler's reachabililty checking.

It's possible that my motivation for the method was:
- to make it more difficult to accidentally operate on `e` intead of `e.getCause()` (as in #7434): If so, I hope that I've addressed that sufficiently by renaming `e` to "`wrapper`".
- to share code with [`wrapAndThrowRuntimeExecutionExceptionOrError` in `SimpleTimeLimiter`](https://github.com/google/guava/blob/5338f7c997dac25879378c9aebb692dc6f6cf9da/guava/src/com/google/common/util/concurrent/SimpleTimeLimiter.java#L278C16-L278C60): I mean, I guess we _could_, but meh, especially since the `Futures` copy of the logic benefits from an implementation comment that wouldn't make sense in the `SimpleTimeLimiter` case.

RELNOTES=n/a
PiperOrigin-RevId: 686551569

Author: cpovirk

android/guava/src/com/google/common/util/concurrent/Futures.java

@@ -1290,22 +1290,17 @@ public String toString() {
     checkNotNull(future);
     try {
       return getUninterruptibly(future);
-    } catch (ExecutionException e) {
-      wrapAndThrowUnchecked(e.getCause());
-      throw new AssertionError();
-    }
-  }
-
-  private static void wrapAndThrowUnchecked(Throwable cause) {
-    if (cause instanceof Error) {
-      throw new ExecutionError((Error) cause);
+    } catch (ExecutionException wrapper) {
+      if (wrapper.getCause() instanceof Error) {
+        throw new ExecutionError((Error) wrapper.getCause());
+      }
+      /*
+       * It's an Exception. (Or it's a non-Error, non-Exception Throwable. From my survey of such
+       * classes, I believe that most users intended to extend Exception, so we'll treat it like an
+       * Exception.)
+       */
+      throw new UncheckedExecutionException(wrapper.getCause());
     }
-    /*
-     * It's an Exception. (Or it's a non-Error, non-Exception Throwable. From my survey of such
-     * classes, I believe that most users intended to extend Exception, so we'll treat it like an
-     * Exception.)
-     */
-    throw new UncheckedExecutionException(cause);
   }
 
   /*

guava/src/com/google/common/util/concurrent/Futures.java

@@ -1377,22 +1377,17 @@ public String toString() {
     checkNotNull(future);
     try {
       return getUninterruptibly(future);
-    } catch (ExecutionException e) {
-      wrapAndThrowUnchecked(e.getCause());
-      throw new AssertionError();
-    }
-  }
-
-  private static void wrapAndThrowUnchecked(Throwable cause) {
-    if (cause instanceof Error) {
-      throw new ExecutionError((Error) cause);
+    } catch (ExecutionException wrapper) {
+      if (wrapper.getCause() instanceof Error) {
+        throw new ExecutionError((Error) wrapper.getCause());
+      }
+      /*
+       * It's an Exception. (Or it's a non-Error, non-Exception Throwable. From my survey of such
+       * classes, I believe that most users intended to extend Exception, so we'll treat it like an
+       * Exception.)
+       */
+      throw new UncheckedExecutionException(wrapper.getCause());
     }
-    /*
-     * It's an Exception. (Or it's a non-Error, non-Exception Throwable. From my survey of such
-     * classes, I believe that most users intended to extend Exception, so we'll treat it like an
-     * Exception.)
-     */
-    throw new UncheckedExecutionException(cause);
   }
 
   /*