Get rid of FreeTemporary. NFC.

Its only use was in a context where it was completely equivalent to
MemFree, so just use that instead, and keep the temporary heap as
purely an arena allocator, that could use something like bump
pointer.

src/mesh.cpp

@@ -110,11 +110,11 @@ void SMesh::Simplify(int start) {
 
     STriMeta meta = l.elem[start].meta;
 
-    STriangle *tout = (STriangle *)AllocTemporary(maxTriangles*sizeof(*tout));
+    STriangle *tout = (STriangle *)MemAlloc(maxTriangles*sizeof(*tout));
     int toutc = 0;
 
     Vector n = Vector::From(0, 0, 0);
-    Vector *conv = (Vector *)AllocTemporary(maxTriangles*3*sizeof(*conv));
+    Vector *conv = (Vector *)MemAlloc(maxTriangles*3*sizeof(*conv));
     int convc = 0;
 
     int start0 = start;
@@ -236,8 +236,8 @@ void SMesh::Simplify(int start) {
     for(i = 0; i < toutc; i++) {
         AddTriangle(&(tout[i]));
     }
-    FreeTemporary(tout);
-    FreeTemporary(conv);
+    MemFree(tout);
+    MemFree(conv);
 }
 
 void SMesh::AddAgainstBsp(SMesh *srcm, SBsp3 *bsp3) {

src/platform/utilunix.cpp

@@ -54,18 +54,6 @@ void *AllocTemporary(size_t n)
     return (void *)&h[1];
 }
 
-void FreeTemporary(void *p)
-{
-    AllocTempHeader *h = (AllocTempHeader *)p - 1;
-    if(h->prev) {
-        h->prev->next = h->next;
-    } else {
-        Head = h->next;
-    }
-    if(h->next) h->next->prev = h->prev;
-    free(h);
-}
-
 void FreeAllTemporary(void)
 {
     AllocTempHeader *h = Head;

src/platform/utilwin.cpp

@@ -47,9 +47,6 @@ void *AllocTemporary(size_t n)
     ssassert(v != NULL, "Cannot allocate memory");
     return v;
 }
-void FreeTemporary(void *p) {
-    HeapFree(TempHeap, HEAP_NO_SERIALIZE, p);
-}
 void FreeAllTemporary()
 {
     if(TempHeap) HeapDestroy(TempHeap);

src/solvespace.h

@@ -150,7 +150,6 @@ void dbp(const char *str, ...);
 std::vector<std::string> InitPlatform(int argc, char **argv);
 
 void *AllocTemporary(size_t n);
-void FreeTemporary(void *p);
 void FreeAllTemporary();
 void *MemAlloc(size_t n);
 void MemFree(void *p);