Update to v5.0 kernel headers.

Test: Builds and boots on taimen.
Change-Id: I13843bf1ab30ea89a50852adc88f2cba8401bded
diff --git a/libc/kernel/uapi/linux/elf.h b/libc/kernel/uapi/linux/elf.h
index 1f69e1b..9845bd3 100644
--- a/libc/kernel/uapi/linux/elf.h
+++ b/libc/kernel/uapi/linux/elf.h
@@ -355,10 +355,12 @@
 #define NT_ARM_HW_WATCH 0x403
 #define NT_ARM_SYSTEM_CALL 0x404
 #define NT_ARM_SVE 0x405
+#define NT_ARM_PAC_MASK 0x406
 #define NT_ARC_V2 0x600
 #define NT_VMCOREDD 0x700
 #define NT_MIPS_DSP 0x800
 #define NT_MIPS_FP_MODE 0x801
+#define NT_MIPS_MSA 0x802
 typedef struct elf32_note {
   Elf32_Word n_namesz;
   Elf32_Word n_descsz;