Propagate test/install options to Glslang. Update Glslang (#1397)

A Glslang test needed an update to work around assumptions of
the sign of a NaN.

Fixes: #1396

DEPS

@@ -7,7 +7,7 @@ vars = {
 
   'abseil_revision': '5be22f98733c674d532598454ae729253bc53e82',
   'effcee_revision' : '19b4aa87af25cb4ee779a071409732f34bfc305c',
-  'glslang_revision': '1e4f53ab2de355296de690583bd26818264b25ff',
+  'glslang_revision': '05ba15169ea4b1471e18305786f12526600a7810',
   'googletest_revision': 'e47544ad31cb3ceecd04cc13e8fe556f8df9fe0b',
   're2_revision': 'c9cba76063cf4235c1a15dd14a24a4ef8d623761',
   'spirv_headers_revision': '4f7b471f1a66b6d06462cd4ba57628cc0cd087d7',

third_party/CMakeLists.txt

@@ -83,6 +83,11 @@ endif()
 
 if (NOT TARGET glslang)
   if (IS_DIRECTORY ${SHADERC_GLSLANG_DIR})
+    if (SHADERC_ENABLE_TESTS)
+      # Glslang tests are off by default. Turn them on if testing Shaderc.
+      set(GLSLANG_TESTS ON)
+    endif()
+    set(GLSLANG_ENABLE_INSTALL $<NOT:${SKIP_GLSLANG_INSTALL}>)
     add_subdirectory(${SHADERC_GLSLANG_DIR} glslang)
   endif()
   if (NOT TARGET glslang)