Bug 1692391 - Remove NS_OBJC_TRY_EXPR_ABORT macro and replace its use with the block version of the macro. r=haik

This macro was quite misguided, too. If evaluating _e raised an exception, then
the expression value of the block would be an uninitialized value. Super unsafe.
It's a good thing that we don't expect "retain" to ever throw.

Differential Revision: https://phabricator.services.mozilla.com/D104954

widget/cocoa/nsCocoaUtils.h

@@ -50,7 +50,9 @@ using mozilla::StaticMutex;
 class nsAutoRetainCocoaObject {
  public:
   explicit nsAutoRetainCocoaObject(id anObject) {
-    mObject = NS_OBJC_TRY_EXPR_ABORT([anObject retain]);
+    NS_OBJC_BEGIN_TRY_ABORT_BLOCK;
+    mObject = [anObject retain];
+    NS_OBJC_END_TRY_ABORT_BLOCK;
   }
   ~nsAutoRetainCocoaObject() {
     NS_OBJC_BEGIN_TRY_ABORT_BLOCK;

xpcom/base/nsObjCExceptions.h

@@ -21,17 +21,6 @@
 
 void nsObjCExceptionLog(NSException* aException);
 
-#define NS_OBJC_TRY_EXPR_ABORT(_e)  \
-  ({                                \
-    typeof(_e) _tmp;                \
-    @try {                          \
-      _tmp = (_e);                  \
-    } @catch (NSException * _exn) { \
-      nsObjCExceptionLog(_exn);     \
-    }                               \
-    _tmp;                           \
-  })
-
 // For wrapping blocks of Obj-C calls. Does not actually terminate.
 #define NS_OBJC_BEGIN_TRY_ABORT_BLOCK @try {
 #define NS_OBJC_END_TRY_ABORT_BLOCK \