Fix type errors in compiler and tests.

In preparation for a float32 build of MuJoCo.

PiperOrigin-RevId: 644407674
Change-Id: I60069f0f865ef89fbf613f5a2ca0c336cc63461e

src/user/user_flexcomp.h

@@ -89,7 +89,7 @@ class mjCFlexcomp {
   // set by user or computed internally
   bool rigid;                     // all vertices are in parent body (all pinned)
   bool centered;                  // all vertex coordinates are (0,0,0) (nothing pinned)
-  std::vector<mjtNum> point;      // flex bodies/vertices
+  std::vector<double> point;      // flex bodies/vertices
   std::vector<bool> pinned;       // is point pinned (true: no new body)
   std::vector<bool> used;         // is point used by any element (false: skip)
   std::vector<int> element;       // flex elements