Migrate to use unified grammar tables

Previously we keep a separate static grammar table for opcodes/
operands per SPIR-V version. This commit changes that to use a
single unified static grammar table for opcodes/operands.

This essentially changes how grammar facts are queried against
a certain target environment. There are only limited filtering
according to the desired target environment; a symbol is
considered as available as long as:

1. The target environment satisfies the minimal requirement of
   the symbol; or
2. There is at least one extension enabling this symbol.

Note that the second rule assumes the extension enabling the
symbol is indeed requested in the SPIR-V code; checking that
should be the validator's work.

Also fixed a few grammar related issues:
* Rounding mode capability requirements are moved to client APIs.
* Reserved symbols not available in any extension is no longer
  recognized by assembler.

1 files changed, 1 insertions, 0 deletions

diff --git a/include/spirv-tools/libspirv.h b/include/spirv-tools/libspirv.h
index 948a6722..a1c8f7d2 100644
--- a/include/spirv-tools/libspirv.h
+++ b/include/spirv-tools/libspirv.h
@@ -73,6 +73,7 @@ typedef enum spv_result_t {
   SPV_ERROR_INVALID_CAPABILITY = -13,
   SPV_ERROR_INVALID_DATA = -14,  // Indicates data rules validation failure.
   SPV_ERROR_MISSING_EXTENSION = -15,
+  SPV_ERROR_WRONG_VERSION = -16,  // Indicates wrong SPIR-V version
   SPV_FORCE_32_BIT_ENUM(spv_result_t)
 } spv_result_t;