layout: merge .bss into .data

This moves the .bss section from "uninitialized" memory that gets
allocated by the loader to explictily zeroed memory in the .data
section.

This makes the loader's job much easier, as it can just map the file in
one contiguous section of memory. Before, it would have to "expand" the
.bss section.

Signed-off-by: Joe Richey <joerichey@google.com>

Author: josephlr

layout.ld

@@ -15,10 +15,9 @@ SECTIONS
 	/* Mapping in the program headers makes it easier to mmap the whole file. */
 	. += SIZEOF_HEADERS ;
 
-	.rodata : { *(.rodata .rodata.*) } :rodata
-	.data   : { *(.data .data.*)     } :data
-	.bss    : { *(.bss .bss.*)       } :data
-	.text   : { *(.text .text.*)     } :text
+	.rodata : { *(.rodata .rodata.*)            } :rodata
+	.data   : { *(.data .data.*) *(.bss .bss.*) } :data
+	.text   : { *(.text .text.*)                } :text
 
 	_end_of_file = . ;