qemu/mcu/arm/mps2.ld: Fix C++ linking.

This commit expands the linkerscript for MPS2-series boards to let C++
code link with the interpreter core.

The linkerscript now contains all necessary sections for C++ code that
uses exceptions to be part of a user module inside the MicroPython
image.

Signed-off-by: Alessandro Gatti <a.gatti@frob.it>

Author: agatti

ports/qemu/mcu/arm/mps2.ld

@@ -22,6 +22,9 @@ SECTIONS
     } > RAM
 
     .ARM.exidx : AT ( _etext ) {
+        . = ALIGN(4);
+        *(.ARM.extab*)
+        *(.gnu.linkonce.armextab.*)
         . = ALIGN(4);
         __exidx_start = .;
         *(.ARM.exidx*)