fix the definitions of ConstTextCoalSection/ConstDataCoalSection

to keep "Text" in sync with the "pure instructions" section attribute.
Lack of this attribute was preventing the assembler from emitting
multibyte noops instructions for templates (and inlines, and other
coalesced stuff) and was causing the assembler to mismatch .o files.

This fixes rdar://8018335

llvm-svn: 108461