mesa: Use explicit casts when precision is lost.

Silences MSVC.

src/mesa/main/get.c

@@ -2133,7 +2133,7 @@ _mesa_GetFloatv( GLenum pname, GLfloat *params )
          params[0] = (GLfloat)(ctx->DrawBuffer->Visual.depthBits);
          break;
       case GL_DEPTH_CLEAR_VALUE:
-         params[0] = ctx->Depth.Clear;
+         params[0] = (GLfloat)(ctx->Depth.Clear);
          break;
       case GL_DEPTH_FUNC:
          params[0] = ENUM_TO_FLOAT(ctx->Depth.Func);
@@ -2936,7 +2936,7 @@ _mesa_GetFloatv( GLenum pname, GLfloat *params )
          GLuint i, n = _mesa_get_compressed_formats(ctx, formats, GL_FALSE);
          ASSERT(n <= 100);
          for (i = 0; i < n; i++)
-            params[i] = ENUM_TO_INT(formats[i]);
+            params[i] = ENUM_TO_FLOAT(formats[i]);
          }
          break;
       case GL_ARRAY_ELEMENT_LOCK_FIRST_EXT: