Rework linker scripts so they work on new version of ld.

Declare output sections with explicit start address - don't rely on LD
    using '.' for the start of the section.  Make addresses that are
    absolute by using the ABSOLUTE() function.
Discard .eh_frame - new gcc has this on by default.
Also, don't use '-d' - instead use FORCE_COMMON_ALLOCATION.
diff --git a/src/rombios.lds.S b/src/rombios.lds.S
index e43822a..a6afe1f 100644
--- a/src/rombios.lds.S
+++ b/src/rombios.lds.S
@@ -16,5 +16,5 @@
                 *(.text16)
                 final_code16_end = . ;
                 }
-        /DISCARD/ : { *(.discard*) }
+        /DISCARD/ : { *(.discard*) *(.eh_frame) }
 }