[PATCH, sanitizer] Wrap rethrow_primary_exception (PR 87880).

[Iain Sandoe]

For some Darwin versions the absence of the rethrow_primary_exception
symbol causes almost all sanitizer tests to fail.

The following patch wraps it as suggested by Jakub in the PR trail, such that
if the gate is not defined, it’s assumed to be available.

OK for trunk?
Iain

libsanitizer/

2019-06-14  Iain Sandoe  <i...@sandoe.co.uk>

        PR libsanitizer/87880
        * asan/asan_interceptors.h:
        (ASAN_INTERCEPT___CXA_RETHROW_PRIMARY_EXCEPTION): New.
        * asan/Makefile.am (DEFS): Add 
        ASAN_HAS_CXA_RETHROW_PRIMARY_EXCEPTION, defined to 0.
        * asan/Makefile.in: Regenerated.

diff --git a/libsanitizer/asan/Makefile.am b/libsanitizer/asan/Makefile.am
index 867240d..b18ab2a 100644
--- a/libsanitizer/asan/Makefile.am
+++ b/libsanitizer/asan/Makefile.am
@@ -3,7 +3,7 @@ AM_CPPFLAGS = -I $(top_srcdir)/include -I $(top_srcdir)
 # May be used by toolexeclibdir.
 gcc_version := $(shell @get_gcc_base_ver@ $(top_srcdir)/../gcc/BASE-VER)
 
-DEFS = -D_GNU_SOURCE -D_DEBUG -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS 
-D__STDC_LIMIT_MACROS -DASAN_HAS_EXCEPTIONS=1 -DASAN_NEEDS_SEGV=1 
-DCAN_SANITIZE_UB=0
+DEFS = -D_GNU_SOURCE -D_DEBUG -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS 
-D__STDC_LIMIT_MACROS -DASAN_HAS_EXCEPTIONS=1 -DASAN_NEEDS_SEGV=1 
-DCAN_SANITIZE_UB=0 -DASAN_HAS_CXA_RETHROW_PRIMARY_EXCEPTION=0
 if USING_MAC_INTERPOSE
 DEFS += -DMAC_INTERPOSE_FUNCTIONS -DMISSING_BLOCKS_SUPPORT
 endif
diff --git a/libsanitizer/asan/asan_interceptors.h 
b/libsanitizer/asan/asan_interceptors.h
index b599ebb..beb1dc9 100644
--- a/libsanitizer/asan/asan_interceptors.h
+++ b/libsanitizer/asan/asan_interceptors.h
@@ -79,7 +79,12 @@ void InitializePlatformInterceptors();
 #if ASAN_HAS_EXCEPTIONS && !SANITIZER_WINDOWS && !SANITIZER_SOLARIS && \
     !SANITIZER_NETBSD
 # define ASAN_INTERCEPT___CXA_THROW 1
-# define ASAN_INTERCEPT___CXA_RETHROW_PRIMARY_EXCEPTION 1
+# if ! defined(ASAN_HAS_CXA_RETHROW_PRIMARY_EXCEPTION) \
+     || ASAN_HAS_CXA_RETHROW_PRIMARY_EXCEPTION
+#   define ASAN_INTERCEPT___CXA_RETHROW_PRIMARY_EXCEPTION 1
+# else
+#   define ASAN_INTERCEPT___CXA_RETHROW_PRIMARY_EXCEPTION 0
+# endif
 # if defined(_GLIBCXX_SJLJ_EXCEPTIONS) || (SANITIZER_IOS && defined(__arm__))
 #  define ASAN_INTERCEPT__UNWIND_SJLJ_RAISEEXCEPTION 1
 # else