Correctly load message from an Error object.

R=mstarzinger@chromium.org
BUG=306220

Review URL: https://codereview.chromium.org/46593010

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@17484 ce2b1a6d-e550-0410-aec6-3dcde31c8c00
Avoid using dd() in Prologue when --optimize-for-size.

When --optimize-for-size is true, the prologue generation outputs the
pre-aging code stub address directly to the instruction stream.  Previously
this was done using dd() which failed if there was any pending constant
pool entries left to be written.  This CL introduces an emit_code_stub_address()
for this purpose instead.

BUG=v8:2968
R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/47743007

Patch from Ross McIlroy <rmcilroy@chromium.org>.

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@17485 ce2b1a6d-e550-0410-aec6-3dcde31c8c00