hclsyntax: return the starting position of a missing attr, not the end. (#97)
hclsyntax: return the starting position of a missing attr, not the end. (#97)

Previously, hclsyntax MissingItemRange() function returned a zero-length
range anchored at the end of the block in question. This commit changes
that to the beginning of the block. In practice, the end of a block is
generally just a "}" and not very useful in error messages.
strivecast/hcl,hashicorp/hcl,hashicorp/hcl,hashicorp/hcl,strivecast/hcl,strivecast/hcl,hashicorp/hcl,strivecast/hcl,strivecast/hcl,hashicorp/hcl