[klibc] x86_64: Use -Ttext-segment to avoid address collision

Building klibc for x86_64 with binutils 2.31 adds an extra
.note.gnu.property section to klibc.so, the address of which is not
affected by the -Ttext option.  Loading a klibc executable then
fails with the following kernel log message:

9409 (sh.shared): Uhuuh, elf segment at 0000000000200000 requested but the memory is mapped already

I don't exactly see why this is happening, but it is triggered by the
new section and the collision can be avoided by passing -Ttext-segment
instead of -Ttext.  A similar change was applied to MIPS recently.

Link: https://www.zytor.com/pipermail/klibc/2019-January/004024.html
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
diff --git a/usr/klibc/arch/x86_64/MCONFIG b/usr/klibc/arch/x86_64/MCONFIG
index fbb6b94..606f041 100644
--- a/usr/klibc/arch/x86_64/MCONFIG
+++ b/usr/klibc/arch/x86_64/MCONFIG
@@ -35,7 +35,7 @@
 # The old default was max-page-size=0x100000, but that also results
 # in a broken layout with binutils 2.30.  Since there's no
 # architectural page size betwen 4 KB and 2MB, set it to 4 KB.
-KLIBCSHAREDFLAGS     = -Ttext 0x00200200 -z max-page-size=0x1000
+KLIBCSHAREDFLAGS     = -Ttext-segment 0x00200000 -z max-page-size=0x1000
 # Asm includes for x86_64 are in the merged x86 tree