Merge branch 'mesa_7_6_branch'

Merge branch 'mesa_7_6_branch'

This should fix the memory leaks in the assembly parser without the
regressions.

The conflicts in program_lexer.l were related to changes in returning
strings between the branches (always return IDENTIFIER vs. returing
either IDENTIFIER or USED_IDENTIFIER).

The conflicts in program_parse.y were related to two changes in master
One change prints a variable name in an error message.  The other
change adds outputVarSize to the OUTPUT_statement rule.  The cause the
position of the IDENTIFIER to change from $2 to $3.

Conflicts:
	src/mesa/shader/lex.yy.c
	src/mesa/shader/program_lexer.l
	src/mesa/shader/program_parse.tab.c
	src/mesa/shader/program_parse.y