Merge pull request #2038 from corporateshark/c_interface

Implemented C-language interface for glslang

diff --cc glslang/MachineIndependent/Versions.h
Simple merge

diff --cc glslang/Public/ShaderLang.h
index 4fe5c7d,e4cb1df..7cfa57b
--- 1/glslang/Public/ShaderLang.h
--- 2/glslang/Public/ShaderLang.h
+++ b/glslang/Public/ShaderLang.h
@@@ -145,8 -149,8 +149,9 @@@ typedef enum 
  typedef enum {
      EShTargetVulkan_1_0 = (1 << 22),                  // Vulkan 1.0
      EShTargetVulkan_1_1 = (1 << 22) | (1 << 12),      // Vulkan 1.1
 +    EShTargetVulkan_1_2 = (1 << 22) | (2 << 12),      // Vulkan 1.2
      EShTargetOpenGL_450 = 450,                        // OpenGL
+     LAST_ELEMENT_MARKER(EShTargetClientVersionCount),
  } EShTargetClientVersion;
  
  typedef EShTargetClientVersion EshTargetClientVersion;