libgo: config HAVE_GETIPINFO

Gccgo configures HAVE_GETIPINFO based on arch/OS. Currently for
the only platform we supported it is available, therefore define
it in config.

This will be important for catching non-call exceptions, where
the IP of the faulting instruction should not be decremented.

Change-Id: I30349b2edf5c06ab371cf9389cf94da02563cbc2
Reviewed-on: https://go-review.googlesource.com/c/gollvm/+/182577
Reviewed-by: Than McIntosh <thanm@google.com>

cmake/modules/ConfigSetup.cmake

diff --git a/cmake/modules/ConfigSetup.cmake b/cmake/modules/ConfigSetup.cmake
index d2fded2..0baeac3 100644
--- a/cmake/modules/ConfigSetup.cmake
+++ b/cmake/modules/ConfigSetup.cmake
@@ -144,3 +144,6 @@
   set(USING_SPLIT_STACK 1)
 endif()
 set(USE_LIBFFI 1)
+
+# _Unwind_GetIPInfo is defined on Linux/AMD46.
+set(HAVE_GETIPINFO 1)

libgo/config.h.cmake

diff --git a/libgo/config.h.cmake b/libgo/config.h.cmake
index 7f0cefe..354c5e3 100644
--- a/libgo/config.h.cmake
+++ b/libgo/config.h.cmake
@@ -156,4 +156,7 @@
 /* Define if the compiler supports -fsplit-stack */
 #cmakedefine USING_SPLIT_STACK 1
 
+/* Define to 1 if _Unwind_GetIPInfo is available. */
+#cmakedefine HAVE_GETIPINFO 1
+
 #endif