Can i compile my shaders to SPIR-V without using glslangValidator?
Typically compiling GLSL to SPIRV would be something you do as part of the build process, so that you end up distributing SPIRV instead of GLSL.  Then you don't need to compile it at runtime.  Assuming you're using the Vulkan SDK, the binary for glslangValidator (or a shell script to build it) should be part of the installed SDK.  

That said, if you want to compile GLSL to SPIRV at runtime, you can link against the glslang library and do that.  Take a look at the Programatic Interface section in the readme.